In this study, the effect of Xue Guan Tong (XGT) on platelet-derived growth factor-A (PDGF-A), PDGF-B and c-myc gene expression of vessel wall was explored with dot blot and in situ hybridization. The results shown that the expression of PDGF-A mRNA in atherosclerotic plaque of the model group was higher, PDGF-A gene hybridizations were mainly distributed in smooth muscle cell which located in newly emerging plaque and edge of atherosclerotic plaque. In contrast, level of PDGF-A mRNA in the XGT group was lower than that in the model group, which indicated that XGT could influence the level of PDGF-A mRNA. The c-myc oncogene expression in the model group was significantly enhanced than that in the normal group. However, the expression in XGT group decreased less than that in the model group. From the results shown above, it suggested that one of the effects of XGT on preventing VSMC proliferation was its influence on PDGF-A and c-myc mRNA expression level.