The polymeric neem oil microcapsule by using toluene-2,4-diiso-cyanate(TDI),polyvinyl alcohol(PVA),glycerol as wall material was produced.The influence factor on the microcapsule reaction was investigated by using the orthogonal experimental design.The optimal conditions of preparing stable solid microcapsule were obtained.The result indicated that the excellent factors were w=15% of PVA,(w=20%) of TDI and w=65% of neem oil.The performance of neem oil microcapsule was analysed preliminarily.The covered effect was tested by assay.This microcapsule had high oil content of 73.29%.Compared with neem oil,the number of larvae and eggs of Phyllotreta striolata and the feeding area were decreased comparatively after treating with neem oil microcapsule.