Conspiracy theory can be described as a subset of false beliefs in which the ultimate cause of an event believed to be due to a plot by multiple actors working together with a clear goal in mind, often unlawfully and in secret. A lot of conspiracy theories are widespread. For example, conspiracy theories relating September 11 terrorist attacks propose that the attack on the Twin Towers was not a terrorist action but a governmental conspiracy. Given these issues, understanding the psychological origins of conspiracy theories becomes an important task for scholars. Concurrently, a large body of research has focused on individual difference correlates of conspiracy theories. This perspective is based on the notion that it is possible to measure conspiracy theory as an individual difference trait. There have been a number of initial efforts to measure individual difference in conspiracy theory. The most prominent specific conspiracy theory scales are Swami and colleague’s Belief in Conspiracy Theories Inventory and Darwin Neave and Holmes’s Conspiracy Theory Questionnaire. However, scales measuring specific conspiracy theory has already shown some defects:(1) most studies have employed novel measurements, with little consideration of the psychometric properties of the measure beyond noting the value of Cronbach’s alpha. (2) items from different scales referring to the same conspiracy theories may not be directly comparable due to differences in wording. (3) Also these scales are closely bound to specific temporal and geographical contexts. There have been some attempts to overcome these shortcomings. First, Brotherton et al. have developed a 15-item Generic Conspiracist Beliefs Scale. Then, Imhoff and Bruder developed a 12-item Conspiracy Mentality Scale. Bruder et al propose the Conspiracy Mentality Questionnaire, a short measure of generic conspiracy theories. Several studies based on these scales have examined association between conspiracy theory and paranoia, the Big Five personality domains, but results have been equivocal with some studies reporting significant associations with openness to experience and agreeableness and other reporting different results. Another class of studies has focused on thinking dispositions, for example, having highlighted the importance of intuitive thinking and need for cognitive closure which will render individuals to less scrutiny of evidence and a desire to learn truth. Other study proposed that conspiracy theories could be explained in terms of the fundamental cognitive errors: conspiracy theorists are more likely to make a dispositional inference about personified actors and susceptibility to the conjunction fallacy. Other scholars noted that the motivation process under conspiracy theories are characterized by need for order and group justification. Yet conspiracy theories have detrimental consequences, both for the individual and for the wider community, including negative civic, health and environment-protecting outcomes. There are evidences that exposure to conspiracy theories reduces intention to engage in politics, to reduce one’s carbon footprint, to vaccinate, and to engage in positive health behaviors. Future research should carry out more experimental studies. More studies should be taken under the Chinese culture background so as to explore the features of Chinese people’s conspiracy theories. Besides, it’s necessary to develop more effective intervention methods which can enlighten the cultivation of citizens’ rational and calm social mentality.