A strain of new virus was isolated from fledgling budgerigars by authors in 1995. Cytopathic effect became visible after the isolate was passaged 4 generations on budgerigar embryo fibroblast and 5 generations on Chicken embryo fibroblast. The SDS PAGE proved that viral capsid was composed of eight polypeptides with molecular weight from 60 000 to 14 500 D. The protein was rich in Asp, Glu and Leu, but comparatively poorer in Arg and Met. The ratio of acidic amino acid to basic amino acid was 1∶2.51. The nucleic acid was dsDNA and existed as s...