State of arts of researches on avian radar systems were introduced, including large avian radar system represented by avian hazard advisory system (AHAS) and airport-based avian radar system represented by Accipiter. An avian radar experimental system was built based on X-band marine radar, and its bird detection feasibility was confirmed separately by operation in alternating horizontal and vertical position for the survey. Two series of avian radar images, which were collected under two scanning modes, were processed respectively by bird target extraction algorithm. After processing of background subtraction, noise suppression, target information extraction and data fusion, avian information was extracted from raw radar images and combined with satellite map or height coordinate system, so flying bird targets distribution situation in survey region was shown visually by fusion images. Finally, performances of avian radar systems at home and abroad were compared and analyzed.