Temperature plays an important role in fertilized egg hatching and the growth of larvae. The effects of temperature on marine fish at early developmental stages have been reported domestically and internationally. Temperatures above the optimal range may cause stress on the growth and increase the mortality rate and the deformity rate. However, the effects of temperature on embryonic development and the larval activity of F1 Epinephelus moara (♀)×E. septemfasciatus(♂) have been unknown. In this study we recorded the hatching rate, deformity rate and survival activity index (SAI) of the embryo and larvae of F1 E.moara (♀)×E.septemfasciatus(♂) at a series of temperatures (13℃, 15℃, 17℃, 19℃, 21℃, 23℃, 25℃, 27℃, 29℃, and 31℃), and identified the optimal temperature for the seed feeding. The good fertilized egg rate after 12 hours of hatching, the hatching rate and the deformity rate of newly-hatched larvae were also recorded. The SAI and survival rate of newly-hatched larvae were measured by not feeding the larvae till death. The results suggested that there was a positive correlation between the embryonic development of F1 and the temperature. The optimal temperature range for hatching was 17-25℃. When the temperature was above 25℃ or below 17℃, the hatching rate decreased and the deformity rate increased. The SAI of F1 first increased and then decreased along with the change in temperature. In the range of 17-21℃, the SAI showed higher values that were 32.14±2.83, 32.30±1.29, and 22.98±1.42 respectively. In conclusion temperature is a very important factor in the process of seed feeding. The optimal water temperature range may be between 17-21℃ for an improved germination rate and reduced mortality and deformity rates.