A kind of organic BN additive of Nitrogen containing heterocycle was synthesized by introducing Nitrogen containing functional groups in the molecular structure to improve the hydrolytic stability organic BN additive,and the tribological properties in rapeseed oil were evaluated by fourball tester.The results indicate that the synthesized organic BN additive has high hydrolytic stability and good wear resistance in rapeseed oil.The B element on the worn surface was studied by Xray absorption nearedge structure spectroscopy (XANES).The surface analyses reveal that the organic BN additive undergoes chemical reactions in the friction process, and the boundary films mainly consisting of B2O3 enhance antiwear properties of rapeseed oil.