The growth of the freshwater shrimp (M. nipponensis) was studied by the month age. Samples were collected from Wuhu Lake from September 1998 to September 1999. From July to January, its growth is isometric growth, but from February to June, it is allometric growth. The relationship between body weight and body length is fitted to power function. In the period from July to January, the value of b is near to 3, but it is obviously smaller than 3 in the p eriod from February to June. The formulas are respectively:1-7 month age old:W_♂=0.0148L^3.2419 (r=0.9978, n=390) W_♀=0.0206L^3.0117 (r=0.9968, n=372) 8-12 month age old:W_♂=0.0857L^2.1788(r=0.9854, n=188) W_♀=0.145L^1.8165 (r=0.9974, n=278). We tried to use Von Bertalanffy and Logistic equations to fit the growth law of the shrimp. In each stage, the respective equations of growth of the body length and body weight of M. nipponensis are:1-7 month age old:♂:L_t=5.374[1-e^{-0.4727(t+0.6009)}](r=0.9835,n=390) W_t=3.4429[1-e^{-0.4727(t+0.6009)}]^3.2419 (r=0.9835, n=390) ♀:L_t=5.86/(1+e^{0.3738-0.3806t})(r=0.9804,n=372) W_t=5.30/(1+e^{2.5143-0.4355t})(r=0.9705, n=372) 8-12monthly old:♂:L_t=7.24/(1+e^{0.1372-0.1126t})(r=0.9822,n=188) W_t=9.50/(1+e^{1.6885-0.1012t})(r=0.9901,n=188) ♀:L_t=6.65/(1+e^{0.2620-0.1375t})(r=0.9910,n=278) W_t=6.40/(1+e^{1.3621-0.1045t}) (r=0.9837, n=278).