Abstract: Experiments proved that the pine moth Dendrolimus spectabilis, D. tabulaeformis, D. punctatus, D. punctatus Wenshanensis and cotton Bollworm Heliothis armigera and silkworm Bombyx mori could be infected by D. spectabilis CPV which was introduced from Japan.The antigens in this test were from D. punctatus which was infected by D. spectabilis CPV from Japan and other pine moths, these antigens were purified by sucrose gradient centrifugation.Antiserum was obtained by immunizing rabbits with purified preparations of virions from CPV of D. punctatus (infected by Japanse D. spectabilis CPV).Serological comparision of virions from above mentioned pine moths was done by absorption test and counter immuno electrophoresis. The results obtained are as follows:The results of the experiments indicated that all pine moth CPVs,no matter whether it is Chinese or Japanese were serologically indistingui shable.Antiserum of pine moth CPV virions did not cross-react with three NPV and one GV.The pine moth CPV and cotton bollworm CPV were found to be serologically closely related, but the pine moth CPV and silkworm CPV could be differentiated using absorption test and counter immuno eletrophoresis technique.