diff --git a/src/route/contents.ts b/src/route/contents.ts
index b995cce..9ea88e4 100644
--- a/src/route/contents.ts
+++ b/src/route/contents.ts
@@ -59,6 +59,12 @@ const ContentQueryHandler = (controller : ContentAccessor) => async (ctx: Contex
 }
 const UpdateContentHandler = (controller : ContentAccessor) => async (ctx: Context, next: Next) => {
     const num = Number.parseInt(ctx.params['num']);
+    if(ctx.request.type !== 'json'){
+        sendError(400,"update fail. invalid content type: it is not json.");
+    }
+    if(typeof ctx.request.body !== "object"){
+        sendError(400,"update fail. invalid argument: not");
+    }
     const content_desc: Partial<Content> & {id: number} = {
         id:num,...ctx.request.body
     };
@@ -130,7 +136,7 @@ export const getContentRouter = (controller: ContentAccessor)=>{
     const ret = new Router();
     ret.get("/search",ContentQueryHandler(controller));
     ret.get("/:num(\\d+)",ContentIDHandler(controller));
-    ret.get("/:num(\\d+)",UpdateContentHandler(controller));
+    ret.post("/:num(\\d+)",UpdateContentHandler(controller));
     ret.use("/:num(\\d+)/:content_type");
     ret.post("/",CreateContentHandler(controller));
     ret.get("/:num(\\d+)/tags",ContentTagIDHandler(controller));