Two heptad repeat regions (HR1, HR2) from F clone of the virulent and avirulent NDV were cloned, expressed with vector pGEX-6p-1 in E. coli BL21 (DE3), and purified the fusion protein by Glutathiones Sepharose 4B Column. After cleaved by precission protease, the desired protein was purified by Glutathione Sepharose 4B Column and high temperature. Purified HR1 and HR2 were analyzed by Mass spectrum, the results shows that the Molecular Weights of HR1 and HR2 of virulent NDV are 7103 and 6301, and the Molecular Weights of HR1 and HR2 of avirulent NDV is 7107 and 6309.