Abstract: In this paper, we present the purification and analysis of some features of nuclear polyhedrosis virus of poplar looper,Apocheima cinerarius. The polyhedrosis inclusion bodies(PIB)were treated respectively by urea, SDS and NaC1 in 0.02M Tris-HCl (pH7.6)-0.005MEDTA buffer. The Virions, released from PIB treated with 0.05M NaCl+0.05M Na₂CO₃,and the nucleocapsids, released from virions treated with 2% Nonidet p-40 (Np-40), were purified with the techniques of sucrose density gradients centrifugation and Sepharose 2B gel column chromatography. Thevirions and nucleoeapsids are different in ultraviolet absorption spectrums. The purity of virions and nucleocapsids was tested by using 10% polyacrylamide gels electrophorese. The process of PIB solution was observed by scanning and transmission electronic microscopy. The analysed results show that DNA content is about 6μg per mg of dry PIB. The determination of 16 kinds amino acids composition of PIB shows that the recovery rate is about 77.09%. The sedimentation coefficient of virions is about 705(S₍₂₀₎^w), and a 57(S₍₂₀₎^w) component part was observed at the same time. The results are discussed in this paper.