The purpose of this study was to determine the growth and reproductive characteristics of round scad Decapterus maruadsi in the East China Sea. The characteristics regarding growth and reproduction of round scad based on otolith reading and gonad histology, respectively, were estimated. The von Bertalanffy’s growth model for round scad was estimated as follows: FL t =342[1−exp{−0.55(t+0.58)}], (1<t<7)
where FL, is fork length (mm) at age in years t. The maturation stage of the ovary was observed by histological techniques. June was the main spawning period; the maturation and migratory nucleus stage of the oocyte was observed when the gonad somatic index value was approximately greater than 4.