GPC and intrinsic viscosity measurements of vinylidene fluoriedchlorotrifluoroethylene copolymer (mole ratio 1: 4) in ethyl acetate at 25 C were done. Based on the principle of GPC universal calibration, a method was developed for determining the Mark-Houwink constants of the system. The values of K=1. 36×10^-3 and α=0. 835 were obtained. When these results are used in the calculation for GPC, the intrinsic viscosity obtained therefrom is well agreeable to that from the viscosity method, and the max relative deviation between the values from two methods is less than 2%.