Two hundred and nine samples were collected to study Coilia mystus. It is found that the maximum body length and weight are 182mm and 23.4g respectively in commercial stock. The minimum body length and weight 94mm and 3.5g respectively, and the individual average K value 3.15×10⁴. The relationship between body length and body weight of Coilia mystus may be expressed as W=1.174×10^-5Z,^2.773.The individual average absolute fecundity and maturity coefficient of female are 7403.48 eggs and 18.92% respectively. The individual average maturity coefficient of male is 8.02%. The relationship between body length or body weight and absolute fecundity can be expressed as F=1.906×10²L^2.54 and F=688.13W-2119.68 respectivaly.