The Spanish marckerel, Scomberomorus commersoni, is one of the major species caught around in the offshore waters of Taiwan. Total annual landings throughout the Taiwan distribution of the species were estimated ever years to be approximately 1000 t . The main fishing gear has drift gillnets, set nets and trawling lines, fishing ground were in Peng-Hu waters. The caught fishing season for the September to April next year. It is spawning season extended from March to June, and peak from April to May Large quantities of Scomberomorus commersoni are caught with the drift gillnets, whether excessive catches this may cause resource implications species. However, the fishes related research in the PengHu waters is still unknown. Therefore, the present study through the reproductive biology, environment and catch of mesh size, would like to know their fishing ground environment, the mature size and suitable mesh size. The research of provide appropriate mesh size and spawning season for this fish species management.