We incubated eggs of the Chinese three-keeled pond turtle (Chinemys reevesii) at 4 constant temperatures to assess the influence of these thermal regimes on incubation length, hatching success, and phenotypic traits of hatchlings. Eggs incubated at 24° and 27°C produced larger hatchlings in body mass, carapace size, and limb length than did those from 30° and 33°C. Hatchlings from 27° and 30°C crawled and swam faster than did their counterparts from 24° and 33°C. The critical thermal minima of hatchlings incubated at 30° and 33°C were higher than those of hatchlings from 24° and 27°C.