When compared with basic theory of mind (ToM), there is very limited research on advanced ToM. The two studies of the current research aimed to explore the underlying mentalistic processes leading to advanced ToM understanding in Strange Stories and possible factors that facilitate the development of advanced ToM from basic ToM. The participants were 25 adolescents with autism spectrum disorder (ASD) and 25 typically developing (TD) peers with matching age (12 to 15) and Verbal IQ. The first study explored the difference in level of difficulty with regard to two groups of stories in the Strange Stories test (Happe, 1994), non-literal and untrue literal. As predicted, stories with non-literal statements were found to be more difficult than untrue literal statements in both ASD and TD groups. With reference to Grice theory, the difference in level of difficulty was suspected to be related to the difference in level of complexity in the mentalistic processes involved. The underlying mentalistic processes of advanced ToM understanding were then explored by extending a hierarchy of 3 mentalistic processes developed from an irony study on TD population (Filippova and Astington, 2008) to other advanced ToM social situations. According to this hierarchy, to detect the speaker’s motivation/ attitude, i.e. advanced ToM understanding, in a statement, one has to first understand the speaker’s belief towards the statement. The speaker’s communication intention would then be identified with reference to this belief. Finally, with understanding at the belief and intention levels as basis, people could interpret the motivation or attitude of the statements. With reference to previous research findings, it was hypothesized that understanding at the motivation/attitude level of non-literal statements would follow the hierarchy of mentalistic processes which reflected more complex mentalistic processes. Understanding of untrue literal statements at motivation/attitude level would involve less complex mentalistic processes as it did not necessarily follow the hierarchy, since understanding of intention and (or) belief was not essential. The results partially supported the hypotheses with some exceptions. Re-categorization according to the adherence to the hierarchy reflected a greater difference between the two new story categories for both ASD and TD groups, which suggested salience in meaning is a better grouping factor to reflect the variation in levels of difficulty among Strange Stories. The factor of “intention and belief” derived from the delineation of mentalistic processes of advanced ToM understanding was found to have significant mediation effects in the link between basic ToM and advanced ToM in the ASD group, which suggested its facilitating role. Yet, the mediation effect was not found in the TD group. The second study investigated the possible facilitating role of knowledge of advanced ToM mental state concepts for the acquisition of advanced ToM. The ASD group was significantly weaker than their TD counterparts in both example and definition level of knowledge of advanced ToM mental state concepts. Similar to the results in Study One, knowledge of advanced ToM mental state concepts was found to be positively associated with advanced ToM understanding but such a relationship was not significant in the TD group. The lack of significant associations among basic ToM, advanced ToM and Intention-Belief as well as the absence of a significant relation between knowledge of advanced ToM mental state concepts and advanced ToM understanding in the TD group indicated the possibility that they are necessary but not sufficient factors for facilitating advanced ToM acquisition. The results shed light on the theoretical framework of advanced ToM acquisition and provided practical implications especially for intervention related to advanced ToM development. / published_or_final_version / Educational Psychology / Doctoral / Doctor of Psychology