Studies on the production of Newcastle disease virus(NDV) were carried out to optimize culture conditions such as initial pH, temperature, serum concentration, multiplicity of infection(M.O.I.) as well as the addition of polycation, antioxidant, and DMSO. Initial pH from 7.2 to 8.1 showed little difference on NDV production but the initial pH below 6.8 resulted in the negative effect. The highest NDV titer was obtained at 0.1 M.O.I. In addition, the maximum production of virus was achieved at 2% FBS and optimum temperature was found to be $34^{circ}C$. Treatment of polycoation increased the virus production. When ascorbic acid was added as an antioxidant, NDV production was also enhanced. Utilization of DMSO, a well-known permeabilizing agent, showed an inhibitory effect on the propagation of NDV.