Abstract: The effect of various additives, such as xanthagenate,ZDDP,sulfurized calcium alkylphenate in formulated lubricant on copper corrosion was evaluated by corrosive bench test (CBT). The corrosion mechanism was also discussed from two aspects of the chemical structure of the additives and their manufacturing processes. It is found that active sulfur amount from homolytic fission of long chain S bridge（Sx，x≥4）and unreacted S element remained in the manufacturing process is the main factor for the Cu corrosion, especially in sulfurized calcium alkylphenates and that there are obvious differences in the structure of the sulfur bridge and the form of the molecule groups in the molecules between sulfurized calcium alkylphenates from different sources.