Sexual dimorphism and geographic variation are common in snakes. The white-lipped pitviper (Trimeresurus albolabris) is a common and widely distributed venomous snake species throughout the Southeast Asia. We report on the sexual dimorphism and geographic variation of T. albolabris in China. Ninety-nine specimens (57 females and 42 males) were examined by using analysis of variance, analysis of covariance, principal component analysis, and other statistical methods for 68 morphological characters. The result showed that T. albolabris displays significant sexual dimorphism in several external characters. Females have a longer snout-vent length, wider anal scales, and larger head size than males, whilst males exhibit a longer tail length and larger number of subcaudal scales. No significant geographic variation was detected, suggesting the absence of obvious morphological differentiation among local populations in China.