Abstract:Leptiuotarsa decemlineata(Say)is a kind of pest insect of international phytosanitary due to its serious harmfulness.Its spreading ways are complicated,its hosts are of wide range,and its ecologfical fitness is strong,It occurs widely in America,Europe,Africa and Asia.At Present,it has been spreadd southwest of the edge of seashire of Bresoviet Union,which is contiguous to Jilin Province and in which the iatitude and weather is similar to Jilin province,This easay discussed the dangerousness and the possibility of existance if Leptiuotarsa decemlineata(Say)spreads into Jinn province on the basis of its distribution and harmfulness,the geographic location of Jilin province,the kinds of its hosts and thecooditions of circumstances of its living,and put forward thd way of controlling its spreading by strengthening the phytosanitary of import,and by making the regular phytosanitaryinvestigation in the boundary area.