This paper describes the reproductive characteristics, embryonic and post-embryonic development of Mudskipper (Periophthalmus modestus) from Qiantang River Estuary (E 30°15', N 121°27'). Fertilized eggs were obtained through a semi-dry artificial fertilization method and were cultured in constant temperature in seawater with weak aeration. Embryonic development of mudskipper was characterized by continual viviperception. The results indicated that the individual absolute fecundity (F) ranged from 1 432 to 2 978 eggs, with an average of 1 998 eggs (n=83). The individual relative fecundity per millimeter (F_L) ranged from 36 to 62 eggs (average 45 eggs) and the individual relative fecundity per gram (F_W) ranged from 528 to 1 530 eggs (average 864 eggs) (n=83). The Gonadosomatic Indexes (GSI) for females and males were 8.47%-25.39% (average 14.49%, n=83) and 0.10%-0.57% (average 0.25%, n=76), respectively. The fertilized eggs were demersal with adhesive filaments and elliptical in shape (0.75±0.02 mm and 0.56±0.03 mm in long-axis and short-axis diameter, respectively, n=300). At the water temperature of 27±0.5℃, salinity of 10 and pH of 7.8±0.3, the embryonic development required 124.13 h and the accumulated temperature was up to 3 351.51 h·℃. Before the larvae were hatched, the organs had already differentiated normally, such as distinct gut, visible anus, air bladder elliptical in shape, and melanophore of eyes. The heart rate could be up to 154.33±5.87 per minute (n=20). Newly hatched larvae (2.17±0.09 mm in total length, n=9) possessed a yolk sac (0.98-1.87 mm in diameter, n=9). The larvae completely absorbed the yolk and started feeding at the third to fourth day after hatching at the water temperature of 27±0.5℃; eleven days after hatching, the tail notochord of larvae became askew up; the upper and lower jaw teeth occurred at eleven and fifteen days after hatching, respectively; twenty-three days after hatching, all fins except the first dorsal fin had been formed. At the whole course, the larvae were feeding on rotifers (Brachionus plicatilis) with the size 0.038-0.074 mm. There were two death peaks, the first was five to seven days after hatching, which was caused by the inability of larvae to eat food, and the second was twenty to twenty-three days after hatching, which was caused by failure of the larvae in the period of metamorphosis to adapt to their environment and the lack of suitable food.