This study was carried out from January to December 2013 in order to determine the species composition of the Gobiidae and Eleotridae; and some biological aspects of the Golden Tank Goby (Glossogobius aureus Akihito & Meguro, 1975). Fish samples were collected in the coastal area Ben Tre province, Mekong delta, Vietnam. Results showed that 35 species of the goby were identified, of which 28 species belong to the family of Gobiidae (80%) and 7 species belong to Eleotridae (20%). The results indicated that G. aureus is one of the commercial important species in the research area. The length-weigth relationship of the G. aureus was determined as W=0.012*L^2.85 (R²=0.958, n=411) and the result indicated that the lowest condition factor (CF) was determined in October, while the highest one in January. Meanwhile the highest gonadosomatic index (GSI) was found in October and the lowest one in January. However, the lowest hepatosomatic index (HSI) was determined in October, while the highest HSI in Jnuary. The absolute fecundity of G. aureus fluctuated from 30,848 to 276,457 eggs/female and the diameter of egg was 0.45±0.026 mm. The length of first maturity (L_m) of G. aureus was L_m=13.02 cm.