Field study was conducted on a flock of broiler chicken in the city of Hama to evaluate the effectiveness of vaccination programs against Newcastle disease, which are used by the live vaccine or the both live and inactivated (inert) vaccine. The flock were divided into two groups, the first have immunized by live vaccine only. Second group were have vaccinated by both live and inactivated vaccine (inert) in age 6 days for both groups. Re-immunization was applied on both groups by live vaccine in age of 26 days. The study showed the effectiveness of the partnership between the two vaccines live and inactivated (inert) were better than the live vaccine only, and the re-vaccinated at age 26 day led to the improvement of the level of the immunity response and the formation of better protection