Aim To investigate the effects of C-type natriuretic peptide (CNP) gene transduction on vascular smooth muscle cell proliferation after angioplasty. Methods Eighty-four rabbits were divided into 3 groups equally:normal,control and test group. The control and test group had been given high-cholesterol diet from 7 d pre-experiment to being killed. All rabbits were fed by high-cholesterol diet. Restenosis models were established by injured iliac artery in control group and test group. In control group, alkaline phosphatase gene that retroviral vector carried was transferred at injured site. In test group,CNP gene that retroviral vector carried was transferred at injured site. Iliac arteries injured were harvested for ~3H-TdR incorporation, immunohistochemistry analysis of proliferating cell nuclear antigen (PCNA). Lumen area, neointimal thickness, neointimal area, neointimal area/media area were measured by image analysing system. Results Iliac arteries injured by balloon, 3 days later, neointimal thickness, neointimal area and neointimal area/media area were increased in control group and test group, and the index was markedly increased after 2 weeks later. The index of test group was less than control group (p<0.05 or p<0.01). Incorporation of ~3 H-TdR became higher 3 days later after balloon angioplasty in control group and test group, but there was no significant difference in two groups (p<0.05). ~3H-TdR incorporation of test group was less than control group 1 week later after balloon angioplasty (p<0.05). ~3H-TdR incorporation of test group was near to normal level 4 weeks later after balloon angioplasty (p<0.05), but there was still higher in control group (p<0.01). Immunohistochemistry staining of PCNA suggested that large numbers of PCNA-positive cells were seen at intima layer 2 weeks later after balloon angioplasty in control group, but there were no conspicuous express in test group. Conclusion Local CNP gene transduction could effectively inhibit vascular smooth muscle cell (VSMC) proliferation and intimal hyperplasia after angioplasty.