Based on the construction of game model including enterprise, competitors and internet consumers, the gains and losses among enterprise, competitors and internet consumers in the game are discussed. And then the inherent mechanism and causes for occurring negative recommendation of internet word-of-mouth are analyzed. Research shows that cooperative motivation between competitors and internet consumers is strong because o f common interests, their alliance is the main cause for occurring negative recommendation; the most effective measures to break the alliance is to reduce their benefits from the alliance and compress their game space.