diff --git a/src/task/imdbTask.ts b/src/task/imdbTask.ts
index 22222d3..4ed0c87 100644
--- a/src/task/imdbTask.ts
+++ b/src/task/imdbTask.ts
@@ -5,7 +5,6 @@ import Movie from "../models/movie";
 
 export async function updateImdbInfo() {
     let movieInfos = await getNewImdbInfos();
-    removeEmptyInfos(movieInfos);
     logResult(movieInfos);
     return updateYahooMovies(movieInfos);
 }
@@ -33,13 +32,6 @@ function filterNeedCrawlMovie({ englishTitle, releaseDate, imdbLastCrawlTime }:
     return shouldCrawl;
 }
 
-function removeEmptyInfos(movieInfos: Movie[]){
-    movieInfos.forEach(info=>{
-        !info.imdbID && delete info.imdbID;
-        !info.imdbRating && delete info.imdbRating;
-    })
-}
-
 function logResult(movieInfos: Movie[]) {
     const foundMovies = movieInfos.filter(movie => movie.imdbID);
     const notfoundMovieIds = movieInfos.filter(movie => !movie.imdbID).map(movie => movie.yahooId);
@@ -48,5 +40,8 @@ function logResult(movieInfos: Movie[]) {
 }
 
 function updateYahooMovies(movieInfos: Movie[]) {
-    return movieInfos.map(imdbInfo => db.updateDocument({ yahooId: imdbInfo.yahooId }, imdbInfo, "yahooMovies"))
+    return movieInfos.map(({ yahooId, imdbID, imdbRating, imdbLastCrawlTime }) => {
+        const newInfo = imdbID ? { imdbID, imdbRating, imdbLastCrawlTime } : { imdbLastCrawlTime }
+        return db.updateDocument({ yahooId }, newInfo, "yahooMovies")
+    })
 }
\ No newline at end of file
diff --git a/src/test/imdbTask.test.ts b/src/test/imdbTask.test.ts
index a6c2787..aeea90f 100644
--- a/src/test/imdbTask.test.ts
+++ b/src/test/imdbTask.test.ts
@@ -44,7 +44,7 @@ describe('imdbTask', () => {
       await updateImdbInfo();
       sandbox.assert.calledWith(stubUpdateDocument,
         { yahooId: yahooMovie.yahooId },
-        { yahooId: yahooMovie.yahooId, imdbLastCrawlTime: moment().format('YYYY-MM-DDTHH') });
+        { imdbLastCrawlTime: moment().format('YYYY-MM-DDTHH') });
     });
   });
 });
\ No newline at end of file