Abstract:Palaemon tenuidactylus Liu et al. is an important commerial shrimp, which lives in brackish estuaries of China. It shows small egg type of developmental pattern. The buds of the first and second pereiopods appear at the first zoeal stage, but the third and fifth at the second zoeal stage, and finally,the fourth at the third zoeal stage. Segmented pereiopods were completed in the fifth zoeal stage. Department of the pleopods in small egg type is delayed too. The buds of the pleopods appear in the sixth zoeal stage. The appendix interna appears at the ninth zoeal stage. Palaemon tenuidactylus and Palaemon gravieri live in the brackish estuaries. The larvae of these are also alike. For the sake of convenience, major different characteristics of the two species are fully given in the present paper.