Lizards exhibit sexual dimorphism in various phenotypic traits and capability performance (e.g. bite force), while the patterns of sexual dimorphism vary among genera and species. The relationship between morphology and function is dynamic, and selective pressures can differentially affect bite performance in different sexes. Here, we analyzed sexual dimorphism in morphological traits and bite force and explored the determinants of bite force in the mountain dragon (Diploderma batangense) from western China. A total of 135 individuals were collected, and nine morphological characteristics and bite force were measured. We found a significant male bias in morphology and bite force performance, with males found to be larger than females in regard to head size, body size, limb length, tail length and bite force, which could be explained by sexual selection. Results also showed that bite force was positively correlated with head size, with the determinant affecting bite force differing between males( mouth length) and females( head width), which may be related to their different roles in reproduction. This study provides a reference for understanding the ecological adaptability of mountain dragons in the field and lays a foundation for revealing the mechanism of bite force variation between the sexes.