A kind of organic BN additive of Nitrogen containing heterocycle was synthesized by introducing Nitrogen containing functional groups in the molecular structure to improve the hydrolytic stability organic BN additive,and the tribological properties in rapeseed oil were evaluated by fourball tester．The results indicate that the synthesized organic BN additive has high hydrolytic stability and good wear resistance in rapeseed oil.The B element on the worn surface was studied by Xray absorption nearedge structure spectroscopy (XANES).The surface analyses reveal that the organic BN additive undergoes chemical reactions in the friction process, and the boundary films mainly consisting of B2O3 enhance antiwear properties of rapeseed oil.