The present study investigated how Chinese children develop theory of mind (ToM) in a language environment with limited mental state talk that is rich in behavior discourse. In Study 1, 60 mothers shared a wordless storybook with their 3-4-year-olds. The children completed two false-belief tasks and the Peabody Picture Vocabulary Test-Revised at the same time and again 1 year later. Mothers' early behavior clarifications during book-sharing predicted children's later false-belief understanding independent of children's early false-belief scores; children's early verbal ability; maternal education; and mothers' early mental state clarifications, simple mental state mentions, and simple behavior mentions. Using a discussion paradigm, Study 2 experimentally exposed 46 children aged 4 to 5 years to mental state or behavior clarifications or physical features of object talk (control group) through storytelling. Children in the experimental groups showed improvement in false-belief tasks from the pretest to the posttest. These findings indicate that behavior clarifications facilitated Chinese children's mental understanding, suggesting a culture-specific mechanism for ToM development.