Mackerel belongs to highly demanded fish nationally and internationally. Since this fish is favored, many of catchment activities also increase. This research was aimed to investigate the biological aspects of mackerel (Rastrelliger sp), based on their length, weight, and gonad maturity level (TKG), related to the condition of the waters/fishing ground as an effort to manage sustainable mackerel in Pandeglang regency. The study area was situated at the fishing ground of mackerel in Pandeglang, Banten. Mackerel were observed from catchment of local fishermen. Mackerel found were then measured for its length and weight. The maturity of gonad was divided into four levels which are I for immature, II for intermediate, III for mature, and IV for over mature. The result showed that mackerel found was 17.40 - 19.28 cm in length and 57.63 - 101.47 g in weight. Based on gender ratio, 55.17% of total caught were male mackerel. According to maturity level, level III and level II were mostly caught followed by level IV and level I. It was indicated that mackerel caught were mating ready and active for growing. Based on this research, should there be management and wise policy from fishermen. This is because if many mackerel of level II and III were caught, it might cause few changes to regenerate new population. Good and sustainable fisheries always include some catchment management. Furthermore any good recommendation on mackerel catchment in related area there should be practiced and applied based on sustainable fisheries principle.