The Qingcaosha reservoir in the Yangtze River estuary is a special system for water supply and the water quality is mainly controlled through biological manipulation methods by Hypophthalmichthys molitrix(H.molitrix) and Hypophthalmichthys nobilis(H.nobilis). A total of 139 tails of H.molitrix and 59 H.nobilis were collected from June 2015 to May 2017. Their ages were identified through the scales or vertebrae, and their growth characteristics were studied based on ages. The results showed that:the age of H.molitrix ranged from 1 to 10 years old and most of them ranged from 3 to 4 years old; The age of H.nobilis was composed of 1 to 11 years old, most of them were 2 or 3 years old. The formula of body length and weight of H.molitrix and H.nobilis were W=0.037 9L^3.027 and W=0.039 0L^2.946 respectively. the functions of Von Bertalanffy in H.molitrix was L_t=77.73[1-e^{-0.183(t+0.60)}],W_t=20 024.3[1-e^{-0.183(t+0.60)}]^3.027, and that in H.nobilis were:L_t=92.11[1-e^{-0.172(t+1.27)}],W_t=23 875.2[1-e^{-0.172(t+1.27)}]^2.946, the growth inflection points of H.molitrix and H.nobilis were 5.24 and 5 years old respectively. So it is recommended that the fishing age of H.nobilis and H.molitrix should be 5.5 years old respectively.