Guangdong bream has bean a chief commercial fish in the Pearl River. A study on the age and growth with reference to its maximum sustaining yield has been conducted. The scale is as good as the aperculum far age determination. The formation of annulus in the scale occurs from March to June every year.The relationship between the radius (R) of the scale and the Length of the body is in linear regression. Thia relationship can be expressed as the formula; L=37.73R+50.52. The relationship between the age (t) and the body length (L) can be expre-seed by the equation; L=472[1一e ^{-0.1989(t+0.1413)}].The Weight (w)-age (t) relati-onship can be described as W=2808.6[1一[1一e ^{-0.1989(t+0.1413)}].The first maturity of the smallest female occurs at 254mm in length,320 grams in weight and. three years of age, while the ms,ie occurs at 215mm in length, 180 grams in weight and two years old. The absolute fecundity ranges from 54,074--375,300 eggs (131,024 eggs on the average).The total mortality of Guangdong bream in the Pearl River was calcuiated to be 0.58, include natural mortality of 0.31 and a catching mortality of 0.27. At present the age class in the harvest is mainly three years old. In such a case it would lee difficult to maintain the maximum sustaining yield. If the catchable age class can be shift to four years of age and the fishing effort is controlled to 0.35, a 16% in-casement in total yield might be expeoted and the primary relative abundance of the reproductive population can be maintained in a stable state.