The gobiid fish species biodiversity in Soc Trang, Vietnam has been carried out along the coastline of Cu Lao Dung and Tran De districts, Soc Trang, Vietnam in the wet and dry seasons. A total sample of 1894 fishes has been caught by deep net (10 mm mesh size), comprising 1006 and 888 fishes in wet and dry seasons, respectively.  These samples were collected in an area of 32 square meters in Cu Lao Dung and Tran De in two seasons. These sample were analysed and identified by morphologic characteristics (7 measured indices and 9 counted indices). The taxonomy of these species were ordered by Fishbase taxonomic classification. The biodiversity indices were quantified by using PRIMER 5 software package, including Shannon, Simpson, Margalef indices. The similarities between two sampling sites and two seasons were also quantified by using this software package. The result indicated that there were 26 species belong to 18 genera, and 2 families (Gobiidae and Eleotridae). Most fish species in study area belonged to Gobiidae (21 species), whereas its counterpart had only 5 species, and there was a similar trend in fish genera composition. Shannon and Simpson values ranged from 2.23 to 2.48 and from 0.80 to 0.89, respectively, and Margalef value was also high ranging from 3.11 to 3.59, suggesting that the fish composition in this study area was high biodiversity. Fish species composition at Cu Lao Dung and Tran De was nearly similar in two seasons (Fig. 1). A total of 1894 fishes was caught in 4 main fieldtrips in a small area, suggesting the gobiid fish species composition in Soc Tran was high diversity, however, it also noted that it was essential to manage the use of the biodiversity.