Recent genome-wide association studies identified the common genetic variants in 9p21 were associated with the coronary artery disease (CAD). However, whether this locus could predict the severity of CAD in Chinese Han population is unclear. 499 CAD patients who underwent coronary angiography (CAG) have been enrolled for this study. The single-nucleotide polymorphisms rs2383207 and rs2383206 in 9p21 were genotyped in 499 CAG cases and 1519 controls in Chinese Han population. The gene dosage of 9p21 was stratified by the degree of vascular lesions and tested for association with the severity of CAD. Rs2383207 and rs2383206 demonstrated significant associations with 2-vessel and 3-vessel disease (P = 2.0×10−3 and 1.9×10−4, respectively). GG genotypes of rs2383206 occurred higher proportion of left main trunk (LM) disease (P = 6.0×10−3). GG genotypes of rs2383207 occurred higher proportion of left anterior descending artery disease (LAD) and right CAD (RCA) (P = 2.7×10−6 and 1.6×10−4, respectively). The risk allele G of rs2383207 was associated with severity of CAD estimated by the Gensini score (P = 3.6×10−5). Rs2383207 may strongly influence the development of CAD in Chinese Han population. The gene dosage in 9p21 could predict the severity of CAD.