diff --git a/Dockerfile b/Dockerfile
index eb06cff..8d1317b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -61,6 +61,14 @@ RUN ruby --version
 RUN apk add php7
 RUN php --version
 
+# Install .NET
+RUN apk add bash icu-libs krb5-libs libgcc libintl libssl1.1 libstdc++ zlib
+RUN apk add libgdiplus --repository https://dl-3.alpinelinux.org/alpine/edge/testing/
+RUN wget https://dot.net/v1/dotnet-install.sh
+RUN bash /dotnet-install.sh -c Current
+RUN ln -s /root/.dotnet/dotnet /usr/local/bin/
+RUN dotnet --version
+
 # Copy files & Install requirements
 RUN addgroup execute
 WORKDIR /HANA
diff --git a/res/test.html b/res/test.html
index 4854176..978172b 100644
--- a/res/test.html
+++ b/res/test.html
@@ -150,6 +150,7 @@
                 KOTLIN: 'kt',
                 RUBY: 'rb',
                 PHP: 'php',
+                CSHARP: 'cs',
             }
 
             const exampleCode = {
@@ -243,6 +244,19 @@
 fscanf(STDIN,"%d %d",$a,$b);
 fprintf(STDOUT,"%d",$a+$b);
 ?>`,
+                CSHARP: `using System;
+
+namespace HANA {
+    class Program {
+        static void Main() {
+            string s = Console.ReadLine();
+            string[] ss = s.Split();
+            int a = int.Parse(ss[0]);
+            int b = int.Parse(ss[1]);
+            Console.WriteLine(a+b);
+        }
+    }
+}`,
             }
 
             const ProblemDataSet = [
diff --git a/src/runner/languages/csharp.ts b/src/runner/languages/csharp.ts
new file mode 100644
index 0000000..d342f65
--- /dev/null
+++ b/src/runner/languages/csharp.ts
@@ -0,0 +1,55 @@
+import { JudgeSourceType, JudgeType } from '../../types/request'
+import { execute, getLimitString, ResultType } from '../util'
+
+export async function build(
+    path: string,
+    uid: string,
+    sourceName: string = 'Main'
+) {
+    await execute(
+        `p-${uid}`,
+        getLimitString(
+            { cpuLimit: 50 },
+            `dotnet new console --force -o ${sourceName} && dotnet publish ${sourceName} --configuration Release --self-contained true --runtime linux-x64`
+        ),
+        { cwd: path }
+    )
+    return {
+        resultType: ResultType.normal,
+        code: 0,
+        stderr: '',
+        stdout: '',
+    }
+}
+
+export function getExecuteCommand(
+    path: string,
+    uid: string,
+    sourceName: string = 'Main'
+) {
+    return `${path}/${sourceName}`
+}
+
+export function getLanguage() {
+    return JudgeSourceType.CSHARP
+}
+
+export function getExtension() {
+    return 'cs'
+}
+
+export function getSupportedType() {
+    return [
+        JudgeType.CommonJudge,
+        JudgeType.Interactive,
+        JudgeType.SpecialJudge,
+    ]
+}
+
+export function getTimeLimit(baseTime: number) {
+    return baseTime
+}
+
+export function getMemoryLimit(baseMemory: number) {
+    return baseMemory
+}
diff --git a/src/types/request.ts b/src/types/request.ts
index d9c3853..a375395 100644
--- a/src/types/request.ts
+++ b/src/types/request.ts
@@ -32,9 +32,10 @@ export const enum JudgeSourceType {
     TYPESCRIPT = 'TYPESCRIPT',
     GO = 'GO',
     RUST = 'RUST',
-    KOTLIN = 'KOTLIN',
+    KOTLIN = '__KOTLIN',
     RUBY = 'RUBY',
     PHP = 'PHP',
+    CSHARP = '__CSHARP',
 }
 
 export interface SourceFile {