Abstract: Using the 45 steel as substrate material and adopting reinforcing treatment technique for surface spraying weld overlying strata, the anti-pitting property of spraying weld tappet/Chinese Stger cam pairs was studied in this paper. The results shown that under the same working conditions, the anti-pitting life of spraying weld tappet heated by oxyacetylene flame is longer one-fold and 4-fold compared with 212 built up welding alloy tappet and tufftride Stger tappet treated with 20Cr gas respectively. In addition, the authors also investigated the mechanism of pitting failure of spraying weld tappets, the anti-pitting properties of surface spraying weld overlying strata and the influence of spraying weld technique on the anti-pitting property of tappet.