he components and structures of T306 (Tricresyl phosphate) and T310A(thiophosphate amine) were analyzed by GC/MS,MS and NMR, and the structure change of contain phosphorus additives in lubricant during FZG test was studied by 31P-NMR spectroscopic techniques. The results show that T306 has good performance of thermal stability and anti wear property, which is suitable for high temperature condition. T310A has excellent oxidation stability, anti wear property and phosphorus retention capacity, which is suitable for high temperature and long cycle working condition. Different phosphorus containing additives possess different thermodynamic stability and are suitable for different working conditions.31-P NMR can be used to estimate the suitable conditions for different phosphorus containing additives and the structure changes of these additives without any pretreatment. The techniques can be used to judge the oil quality through monitoring the structure change of contain phosphorus additives in lubricant.