There are many factors that drive the exploitation of blue swimming crab in East Aceh waters. Therefore, appropriate management efforts are needed in order to preserve the life of blue swimming crab. Evaluation of the biological aspects of the blue swimming crab population in East Aceh waters has a major role in drafting regulations. This study aims to determine the biology of the blue swimming crab population in the waters of East Aceh. This research was conducted in June 2024 in the waters of East Aceh. The method used was survey method. Blue swimming crab samples were taken randomly from crab fishermen as much as 10% of the catch. Sampling once a week at 2 different locations for 1 month. The results showed that the relationship between carapace width and weight of male and female blue swimming crab (Portunus pelagicus) had a negative allometric growth pattern because the value of b < 3, namely 1.65. The sex ratio of blue swimming crab is not 1:1 or unbalanced. Male blue swimming crab gonad maturity is mostly at level I, while females can reach gonad maturity at level II. Key words: Blue swimming crab, biology, East Aceh.