diff --git a/compiler/include/zamalang/Dialect/MidLFHE/IR/MidLFHEOps.td b/compiler/include/zamalang/Dialect/MidLFHE/IR/MidLFHEOps.td
index 0273e0380..d7d5c47e4 100644
--- a/compiler/include/zamalang/Dialect/MidLFHE/IR/MidLFHEOps.td
+++ b/compiler/include/zamalang/Dialect/MidLFHE/IR/MidLFHEOps.td
@@ -29,6 +29,17 @@ def AddPlainOp : MidLFHE_Op<"add_plain"> {
     ];
 }
 
+def MulPlainOp : MidLFHE_Op<"mul_plain"> {
+    let arguments = (ins CipherTextType:$a, AnyInteger:$b);
+    let results = (outs CipherTextType);
+
+    let builders = [
+        OpBuilder<(ins "Value":$a, "Value":$b), [{
+            build($_builder, $_state, a.getType(), a, b);
+        }]>
+    ];
+}
+
 def PBSRegion : Region<
   CPred<"::mlir::zamalang::predPBSRegion($_self)">,
   "pbs region needs one block with one any integer argument">;
diff --git a/compiler/tests/Dialect/MidLFHE/op_add_plain.mlir b/compiler/tests/Dialect/MidLFHE/op_add_plain.mlir
index fc1946264..db4b31710 100644
--- a/compiler/tests/Dialect/MidLFHE/op_add_plain.mlir
+++ b/compiler/tests/Dialect/MidLFHE/op_add_plain.mlir
@@ -1,45 +1,45 @@
 // RUN: zamacompiler %s  2>&1| FileCheck %s
 
-// CHECK-LABEL: func @add_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext
-func @add_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext {
+// CHECK-LABEL: func @mul_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext
+func @mul_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext {
   // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
-  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.ciphertext, i32) -> !MidLFHE.ciphertext
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.mul_plain"(%arg0, %[[V1]]) : (!MidLFHE.ciphertext, i32) -> !MidLFHE.ciphertext
   // CHECK-NEXT: return %[[V2]] : !MidLFHE.ciphertext
 
   %0 = constant 1 : i32
-  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.ciphertext, i32) -> (!MidLFHE.ciphertext)
+  %1 = "MidLFHE.mul_plain"(%arg0, %0): (!MidLFHE.ciphertext, i32) -> (!MidLFHE.ciphertext)
   return %1: !MidLFHE.ciphertext
 }
 
-// CHECK-LABEL: func @add_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024>
-func @add_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024> {
+// CHECK-LABEL: func @mul_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024>
+func @mul_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024> {
   // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
-  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.lwe<1024>, i32) -> !MidLFHE.lwe<1024>
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.mul_plain"(%arg0, %[[V1]]) : (!MidLFHE.lwe<1024>, i32) -> !MidLFHE.lwe<1024>
   // CHECK-NEXT: return %[[V2]] : !MidLFHE.lwe<1024>
 
   %0 = constant 1 : i32
-  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.lwe<1024>, i32) -> (!MidLFHE.lwe<1024>)
+  %1 = "MidLFHE.mul_plain"(%arg0, %0): (!MidLFHE.lwe<1024>, i32) -> (!MidLFHE.lwe<1024>)
   return %1: !MidLFHE.lwe<1024>
 }
 
-// CHECK-LABEL: func @add_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12>
-func @add_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12> {
+// CHECK-LABEL: func @mul_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12>
+func @mul_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12> {
   // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
-  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.glwe<1024,12>, i32) -> !MidLFHE.glwe<1024,12>
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.mul_plain"(%arg0, %[[V1]]) : (!MidLFHE.glwe<1024,12>, i32) -> !MidLFHE.glwe<1024,12>
   // CHECK-NEXT: return %[[V2]] : !MidLFHE.glwe<1024,12>
 
   %0 = constant 1 : i32
-  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.glwe<1024,12>, i32) -> (!MidLFHE.glwe<1024,12>)
+  %1 = "MidLFHE.mul_plain"(%arg0, %0): (!MidLFHE.glwe<1024,12>, i32) -> (!MidLFHE.glwe<1024,12>)
   return %1: !MidLFHE.glwe<1024,12>
 }
 
-// CHECK-LABEL: func @add_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2>
-func @add_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2> {
+// CHECK-LABEL: func @mul_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2>
+func @mul_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2> {
   // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
-  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.ggsw<1024,12,3,2>, i32) -> !MidLFHE.ggsw<1024,12,3,2>
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.mul_plain"(%arg0, %[[V1]]) : (!MidLFHE.ggsw<1024,12,3,2>, i32) -> !MidLFHE.ggsw<1024,12,3,2>
   // CHECK-NEXT: return %[[V2]] : !MidLFHE.ggsw<1024,12,3,2>
 
   %0 = constant 1 : i32
-  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.ggsw<1024,12,3,2>, i32) -> (!MidLFHE.ggsw<1024,12,3,2>)
+  %1 = "MidLFHE.mul_plain"(%arg0, %0): (!MidLFHE.ggsw<1024,12,3,2>, i32) -> (!MidLFHE.ggsw<1024,12,3,2>)
   return %1: !MidLFHE.ggsw<1024,12,3,2>
 }
\ No newline at end of file
diff --git a/compiler/tests/Dialect/MidLFHE/op_mul_plain.mlir b/compiler/tests/Dialect/MidLFHE/op_mul_plain.mlir
new file mode 100644
index 000000000..fc1946264
--- /dev/null
+++ b/compiler/tests/Dialect/MidLFHE/op_mul_plain.mlir
@@ -0,0 +1,45 @@
+// RUN: zamacompiler %s  2>&1| FileCheck %s
+
+// CHECK-LABEL: func @add_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext
+func @add_plain_ciphertext(%arg0: !MidLFHE.ciphertext) -> !MidLFHE.ciphertext {
+  // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.ciphertext, i32) -> !MidLFHE.ciphertext
+  // CHECK-NEXT: return %[[V2]] : !MidLFHE.ciphertext
+
+  %0 = constant 1 : i32
+  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.ciphertext, i32) -> (!MidLFHE.ciphertext)
+  return %1: !MidLFHE.ciphertext
+}
+
+// CHECK-LABEL: func @add_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024>
+func @add_plain_lwe(%arg0: !MidLFHE.lwe<1024>) -> !MidLFHE.lwe<1024> {
+  // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.lwe<1024>, i32) -> !MidLFHE.lwe<1024>
+  // CHECK-NEXT: return %[[V2]] : !MidLFHE.lwe<1024>
+
+  %0 = constant 1 : i32
+  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.lwe<1024>, i32) -> (!MidLFHE.lwe<1024>)
+  return %1: !MidLFHE.lwe<1024>
+}
+
+// CHECK-LABEL: func @add_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12>
+func @add_plain_glwe(%arg0: !MidLFHE.glwe<1024,12>) -> !MidLFHE.glwe<1024,12> {
+  // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.glwe<1024,12>, i32) -> !MidLFHE.glwe<1024,12>
+  // CHECK-NEXT: return %[[V2]] : !MidLFHE.glwe<1024,12>
+
+  %0 = constant 1 : i32
+  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.glwe<1024,12>, i32) -> (!MidLFHE.glwe<1024,12>)
+  return %1: !MidLFHE.glwe<1024,12>
+}
+
+// CHECK-LABEL: func @add_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2>
+func @add_plain_ggsw(%arg0: !MidLFHE.ggsw<1024,12,3,2>) -> !MidLFHE.ggsw<1024,12,3,2> {
+  // CHECK-NEXT: %[[V1:.*]] = constant 1 : i32
+  // CHECK-NEXT: %[[V2:.*]] = "MidLFHE.add_plain"(%arg0, %[[V1]]) : (!MidLFHE.ggsw<1024,12,3,2>, i32) -> !MidLFHE.ggsw<1024,12,3,2>
+  // CHECK-NEXT: return %[[V2]] : !MidLFHE.ggsw<1024,12,3,2>
+
+  %0 = constant 1 : i32
+  %1 = "MidLFHE.add_plain"(%arg0, %0): (!MidLFHE.ggsw<1024,12,3,2>, i32) -> (!MidLFHE.ggsw<1024,12,3,2>)
+  return %1: !MidLFHE.ggsw<1024,12,3,2>
+}
\ No newline at end of file