This paper collected 98 pieces of rumor denials from Monthly List of Rumor about “science” issued by Beijing，and analyzed constitute elements of every rumor denials and their theoretical effect according to results of previous rumor empirical research. Results indicated that：① Only 29% of rumor denials introduce source，of which about 89% can be deemed to be trusted；② All rumor denials contain introduction of rumors which may lead audience to recall rumor as “truth”；③ About 65% of rumor denials contains rumors refuting，of which 11% may lead audience to believe rumors more；④ About 82% of rumor denials contain statements of truth，of which only 4% contain analysis of reason of audience believing rumors，which can reduce impact of rumors significantly. ⑤ Only 23% of rumor denials contain arousal of reverse emotion，in other words，77% of rumor denials couldn’t eliminate effect of rumors to behavior of audience completely.