This study aimed to analyze spatial and temporal size abundance and sex ratio patterns of blue swimming crab (BSC). It was conducted from June to December 2018. Samples were taken monthly using collapsible pots and gillnets from different habitat characteristics of intertidal (station A), river mouth (station B), seagrass (station C and D), and depth of > 30 m (station E). Each sample was sexed, measured its CW (cm), and weighed its body weight (g). Those were classified according to sex and CW into: < 6.0 cm (juvenile), ≥ 6.0 - 9.0 cm (mature), and ≥ 9.0 cm (adult) and counted to perform abundance and sex ratio of each station and month. Results showed that juveniles were more abundant in station A, while mature abundance has no distribution pattern. Adults tended to be abundant in station E. Those may affect sex ratio in all stations and months. Male juvenile sex ratio preponderated over female in station A, while in other stations have no pattern. On the contrary, mature females preponderated over males in station A, but have no pattern in other stations, while adults showed females preponderated over males in station E. It implies that females of the blue swimming crab (BSC = Portunus pelagicus) prefer deep water having high salinity to release eggs.