Research about spermatogenesis and the structure of the androgenic gland in Eriocheir sinensis showed that there was a close relationship between the androgenic gland and spermatogenesis. There was no spermatid when the androgenic gland was in the primary development phase . With the AG development, a great number of primary and secondary spermatocytes appeared in the seminiferous tubules. Later, the sperms matured and were released when the androgenic gland was in the secretion phase.