This study was carried from May 2014 to April 2015 to understand basic biological population parameters of the red goby Trypauchen vagina. The analysis of 328 fish specimens (161 males and 167 females) collected from Kinh Ba River, Cu Lao Dung, Soc Trang showed the sex ratio of this goby was about 1:1 The length-frequency data of this goby was subjected to FiSAT II software to estimate its population indexes, which showed that this species was high growth rate due to the high value of growth index (K= 0.41/yr.) and high natural mortality (M = 1.14/yr.). The total mortality (Z = 1.57/yr.) and fishing (F = 0.43/yr.) mortalities of this goby were low, and its exploitation rate (E = 0.270) was nearly equal to optimal exploitation rate (E50 = 0.278). Although population of this goby had a great potential for fishing due to high value of maximum exploitation rate (Emax= 0.421), local authorities and fishermen should maintain the current exploitation rate for future sustainable management of this fish resource.