Abstract: In order to improve the survival rate of larval breeding of Holothuria leucospilota and provide a theoretical basis for the development and utilization of wild resources of tropical sea cucumber, we investigated the effects of salinity on the growth, development and survival rate of planktonic larvae of H. leucospilota by measuring the growth and development of the planktonic larvae under different salinity conditions and analyzing the effects of body length, stomach width and survival rate of the planktonic larvae on its growth. Results demonstrate that the specific growth rates (SGR) of body length in the salinity groups of 33 and 36 were significantly higher than those in the other salinity groups (P<0.05), and there was no significant difference between the salinity group of 24 and 27, 33 and 36 (P>0.05). When the salinity was 30, the SGR of larval stomach width was significantly higher than that in the other salinity groups (24, 33 and 36 salinity groups, P<0.05). When the salinity was 27−30, the development and survival rate of stomach of planktonic larvae were the best, and its overall shape was stronger and clearer. Therefore, 27−30 is the optimal salnility for the development of plankton larvae of H. leucospilota.