Hemifusus tuba (Gmelin) is a commercially valued species that naturally lives in the South China Sea. In order to study the reproductive biology of H. tuba, 216 mature individuals captured from the North Bay were measured. The reproductive habit, season and reproductive capacity, hatching development and development course of naiad and young H. tuba were determined, and the whole process embryonic development was observed and photographs were taken continuously. Based on the annual change of cultural experiments, it was concluded that the reproductive season of H. tuba was from April to May (24-28 ℃) every year in inshore Guangxi. The course of embryonic development occurred completely in egg capsule of H. tuba. It belongs to the direct developmental type. After hatching, it directly become naiad H. tuba and had no free life stage of larva. The parents mate many times in a reproductive period. The female spawns 2.1 times and lays 20.4 egg capsules in the average every reproductive period. The individual reproductive capacity is 43 thousands on the average. There are average 2 115 zygotes in an egg capsule, and the diameter of eggs was 240-320 μm, and only 10-30 could develop into naiads among them. Under 24-29 ℃, the naiad hatched after 29-30 days. Hatching rate is 98%. The juvenile developed into naiad and grew into 5.0 cm young H. tuba after 90 days. The reproductive habit, season and reproductive capacity, hatching development and development course of naiad and young were first reported in H. tuba. These results would provide the important scientific basis for the largescale artificial reproduction and the resources protection of H. tuba. And the optimal season of artificial reproduction is from April to May.