Tridentiger trigonocephalus widely distributed at the Yangtze River estuary with abundant population. Young T. trigonocephalus is an important prey for many aquatic animal species at the Yangtze River estuary. However, studies of effects of ecological factors on the early life stages of T. trigonocephalus are scarce. Because of pollution and large scale constructions, the environmental conditions of the Yangtze River estuary have been changing recently. It is necessary to understand the effects of environmental changes on the early life stages of fishes in the estuarine area. In this study, the ecological adaptability of embryos and larvae of T. trigonocephalus were investigated. The experimental results showed that the fertility rate and hatching rate reduced with the increase of water temperature. Temperature ranging from 17℃ to 21℃ is an optimal water temperature for the development of the embryos. The model of effective accumulative temperature for the embryonic development is N = 3128.3 / (T-4.36), and the range of temperature coefficient Q10 was from 1.33 to 2.84. The larva development speeded up, but the survival rate reduced with the increase of temperature. The embryonic development speeded up, but the hatching rate reduced when the photoperiod was increased. Moreover, the larval development also speeded up with the increase of photoperiod. The embryonic development speeded up and the hatching rate rose with the increase of pH value. The larva development also speeded up and the abnormality rate rose with the increase of pH value, e.g., the activity ability of high pH value groups (pH 7.5, pH 8.5 and pH 9.5) was better than that of low pH value groups (pH 4.5, pH 5.5 and pH 6.5). In conclusion, the optimal ecological factors for the early life development of T. trigonocephalus were 17℃ to 21℃ of water temperatures, over 12-hour of daily photoperiod, and 7.5 to 9.5 of pH values. It may be inferred that the early life development and the population dynamics of T. trigonocephalus may be influenced by the environmental alteration at the Yangtze River estuary.