Abstract: In a 60 d trail, the daily weight gain per fish in the group which were fed compound feed supplementing Pennisetum americanum?P.purpureum was 15.61?0.14 g, that in the group supplementing Vigna stnensis sari Var was 15.03?0.34 g,both of them were higher than that of CK (fed compound feed only, 9.66?0.26 g).Variance analysis showed there were significant differences (P0.01)between treatments and CK.It demonstrated that feeding Pennisetum americanum?P.purpureum and Vigna sinensis sari Var significantly improved the weight gain of grass carp.In addition, feeding forages increased the aminoacid level of back muscle of grass carp, enhanced the contents of human requisite aminoacids and taste aminoacids in the fish body.