We incubated 84 eggs of the Asian yellow pond turtle (Mauremys mutica) from a hatchery in Guangzhou (the southern population) at three constant temperatures (26, 28 and 30℃) to assess the effects of temperature on incubation period, hatching success and hatchling traits (sexual phenotype, body size, righting performance and post-hatching growth). Because physiological and behavioral performances of reptiles are sensitive to temperature, we conducted to measure righting performance and post-hatching growth at the body temperature of 28℃. The righting response was assessed for each turtle in a temperature-controlled room on the second day of post-hatching. The turtles were placed upside down in an open area and their performance trials were recorded using a digital camera. Righting time was defined as the time required for a turtle to right itself after it began to move. After the righting trials, all turtles were reared in constant-temperature aquaria for about three months to evaluate the early growth and identify the sex by between-sex differences in morphological traits. Within the range of 26-30℃, hatching success increased with increasing incubation temperatures but, statistically, it did not differ among the three temperature treatments. Incubation period (the number of days from oviposition to pipping) was independent of initial egg mass within each temperature treatment, and decreased with increasing incubation temperature. The sex ratio of hatchlings varied among the three temperature treatments, with the treatments of 26℃ and 28℃ both leading to a male-biased sexual ratio, and the treatment of 30℃ to a female-biased sexual ratio. Hatchling mass and size (carapace length, width and height) were dependent on initial egg mass. Therefore, one-way analysis of covariance (ANCOVA) with egg mass as the covariate was used to examine the effects of incubation temperature on these traits. Temperature affected carapace length, width and body mass, but not carapace height. Hatchlings from the 30℃ treatment were larger than those from the 26℃ treatment after accounting for egg mass. This result was not consistent with those documented in a number of other studies where eggs incubated at relatively low temperatures produce larger hatchlings. The production of smaller hatchlings may result from an increased energy expenditure associated with a prolonged incubation length. A hatchling's righting performance was affected by incubation temperature. The proportion of hatchlings that successfully righted within 10 minutes was greater in the 28℃ (60.0%, 15/25) and 30℃ (64.3%, 18/28) treatments than in the 26℃ treatment (23.8%, 5/21); the mean righting time was shortest in the 30℃ treatment and longest in the 26℃ treatment, with the 28℃ treatment in between. Post-hatching growth differed among the three treatments. The daily growth rates of carapace length, width and body mass were highest in hatchlings from the 26℃ treatment and lowest in hatchlings from the 30℃ treatment, with hatchlings from the 28℃ treatment in between. The differences in hatchling growth among the three treatments might partly stem from the between-sex difference in growth rate, as revealed by the fact that male hatchlings from low-temperature treatments grew faster than females from high-temperature treatments. The mean incubation period was longer, and the pivotal temperature (the temperature that yields a 1:1 offspring sex ratio) was higher, in the southern population than in the northern population, presumably reflecting different adaptation to local thermal environment.