Abstract: In order to rapidly detect and identify airborne Newcastle disease virus (NDV) in the indoor air and outdoor air of largescale commercial broiler house, international standard air collectorAGI30 was used to collect the air, Oropharyngeal and cloacal swabs were also collected. NDVs in the air samples and in the swaps were detected and virulence identified by degenerate primers based RTPCR; at the same time NDVs in the samples were isolated and purified and then were virulence identified by conventional biological pathogenicity methods. The results showed that both virulent virus and avirulent virus could be detected simultaneously in 2/ 15 indoor air samples and 4/15 swaps, avirulent virus could be singly detected in 3/15 indoor air samples and 13/15 swaps, no virus could be detected in the air of 5 m upwind samples, avirulent virus could be singly detected in 1/3 samples of 5 m downwind air, no virus could be detected in all the other samples by degenerate primers based RTPCR. Three virulent NDV and four avirulent NDV were isolated and virulence identified in the RTPCR positive samples and no virus was isolated from the RTPCR negative samples. The results suggest that degenerate primers based RTPCR can detect and virulence identify NDV directly and rapidly.