Many PX events have happened in China since 2007 with rumors about the toxicity of PX and harmfulness of PX project and effectiveness of government executive power. Under the circumstances of the lack of official information and the decline of media credibility，rumors appear. In reverse，rumors have unpredictable impact on PX events. This paper analyses the content features，generation mechanism and communication mechanism of PX rumors，aiming to hold the communication rules of PX rumors and give advice to get rid of rumors on similar events.