"Theory of mind" refers to the competence to understand the mental states of oneself and others, such as perception, emotion, intention, belief, etc. (Baron-Cohen, 2001). Existing literature suggests that the abilities to understand mental states are associated with pretend play behaviors in children. However, the theory theory (Perner, 1991) and the simulation theory (Harris, 2000) have provided different interpretations about their relations because the two theories have different views concerning the cognitive mechanism underlying the development of theory of mind. / Results from the three studies were not in support of either theory fully and consistently. Specifically, the result of Study 1 showed that the children understood the false belief of others before they understood the false belief of oneself's. This result was inconsistent with both theories. Results of Study 2 indicated that children' understanding of false belief was associated only with social pretend play, but not with oneself's pretend play. However, considering the concept of multiple models of representations could be used to explain the relation between pretend play and false belief understanding abilities and has no theory inclination, it could not give evidence to the comparison between the two theories through these ways and results of the relation examination in this study. The results of the intervention study demonstrated that only the training method that involved the discussion of multiple identities of oneself produced significant and positive effect on children's false belief understanding. In brief, the theory theory was considered to obtain stronger support from the present research. / The present research compared the two theories by investigating the relations between children's pretend play and their false belief understanding abilities. Three studies were conducted, that involved preschool children from 3-years-old to 5-years-old from a remote area in the eastern part of China, to address three questions on that the two theories pose different predictions. The first question was concerned with whether or not there IS a developmental sequence between understanding the mental states of oneself and understanding others' (Study 1). The second question was about whether or not the abilities to understand mental states are associated with oneself's pretend playas well as with social pretend play (Study 2). The third question was related to whether or not two types of social pretend play interventions that were designed based on the two theories respectively would significantly affect children's competence to understand false belief by comparing the two intervention groups with a control group (Study 3). The intervention method towards the theory theory involved an explicit discussion of multiple identities of oneself whereas the intervention reflecting the simulation theory did not have the discussion. / 董及美. / Adviser: Yu-Jing Ni. / Source: Dissertation Abstracts International, Volume: 73-04, Section: A, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 187-194). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Dong Jimei.