Skeletal system remodeling of tadpoles, which occurs during amphibian metamorphosis, adapts them to the change from aquatic habitat to land habitat. In this study, the vertebrae skeletons of Bufo gargarizans tadpole at different stages (Gosner 38-46) were investigated using double staining with alcian blue and alizarin red. The results showed that the neural arch laminae fused at the midline at gosner stage 39. The centra and neural arch of presacrals Ⅰ-Ⅷ and sacral started to ossify at gosner stage 42, then the transverse processes of presacrals Ⅰ-Ⅷ, sacrum, hypochord, postsacral Ⅰ and postsacral Ⅱ began to ossify; finally the urostyle formed at gosner stage 46. The formation of the urostyle by the fusion of the postsacral veterbrae reflects the functional adaption of anuran larval skeletal system for transformation from aquatic to terrestrial environment.