The present study was aimed to investigate the role of cyclin D1 in human pulmonary artery smooth muscle cells (HPASMCs) proliferation and migration induced by cigarette smoke extract (CSE). The eukaryotic expression vector of antisense cyclin D1 gene (pIRES2-EGFP-ascyclin D1) was recombinated. The recombinant and empty vector were separately transfected into normal HPASMCs using liposome. Then the cells were treated with or without 5% CSE. The cells were randomly divided into six groups: control group, vector group, antisense cyclin D1 group, 5% CSE group, vector+5% CSE group and antisense cyclin D1+5% CSE group. The expressions of cyclin D1 mRNA and protein were detected by real-time fluorescence RT-PCR and Western blot, respectively. The proliferation of HPASMCs was examined by cell cycle analysis, MTT assay and proliferation cell nuclear antigen (PCNA) immunocytochemical staining. The migration of HPASMCs was measured by Transwell cell test. The results showed that the eukaryotic expression vector of antisense cyclin D1 gene was constructed and transfected into HPASMCs successfully. The cyclin D1 mRNA and protein levels in antisense cyclin D1 group were significantly lower than those in control group (P<0.05). In 5% CSE group, the cyclin D1 mRNA and protein levels were elevated significantly compared with those in control group (P<0.05), and the indicators of cell and migration in antisense cyclin D1+5% CSE group were remarkably lower than those in 5% CSE group (P<0.05). These results suggest that CSE could promote HPASMCs proliferation and migration through up-regulation of cyclin D1 expression. PIRES2-EGFP-ascyclin D1 could attenuate CSE-induced proliferation and migration of HPASMCs by suppressing the expression of cyclin D1, which implicates that cyclin D1 might be involved in the process of HPASMCs proliferation and migration stimulated by CSE.