Abstract: According to the problem that the antenna pattern of large phased array radar can not be obtained in real-time by mid-field or far-field method, a novel algorithm that uses scanning pattern as an alternative to antenna pattern is proposed for antenna acceptance. The scanning pattern and antenna pattern expressions of sum beam and difference beam are derived from the theory respectively, then the effects of element pattern to scanning pattern and antenna pattern are studied, which points out a conclusion that the scanning pattern and the antenna pattern are approximately equivalent in the main lobe of element pattern. Simulation and experiment results all indicate that each performance index of scanning pattern and antenna pattern are equivalent. The conclusion of the paper can be used to guide acceptance of digital array radar antenna on the basis of scanning pattern for radar system designer.