Abstract Numerous studies have show that children’s language ability is not only related to false-belief understanding, but also appeared to play an important role in the development of theory of mind (ToM). However, it remained unclear which aspect of language development contributes most to the development of ToM. Many researchers such as Moore et al. (1994) and de Matsui et al. (2006) argue that the mental state language of particular languages might be related to children’s theory of mind development. This study explored the relationship between preschoolers’ flase belief understanding and the using of mental state terms within a storytelling task. Using 101 children aged 3-5 in the kindergarten as subjects, the study adopted a short-term longitudinal design which was administered twice at three-month intervals, so that children’s mental state discourse at Times 1 and 2 could both be related to false belief assessed at Time2. This study was designed to examine children’s mental state discourse within a storytelling task, in which children were asked to generate responses to a series of photographs, and assess using a set of false belief tasks, including unexpected transfer, unexpected content and appearance-reality task. The results showed these two are very close to each other. Within Picture talking, preschoolers used fewer belief terms than desire terms and emotional terms, and vocabulary types of the cognitive terms were less, mainly ‘yao4’ and ‘xiang3’. Furthermore, only on the first test, control the general language ability and age, there was still a remarkable correlation beween children’ emotional terms , belief terms and false belief understanding in the same period, even later false belief understanding, but there wasn’t evident correlation between the false belief task performance at time1 and the mental state language at time2. The results of this short-term longitudinal study provide some support for the important role of verbal skills plays in the development of ToM, particularly the mental state language.