Small ubiquitin-like modifier 1 (SUMO1) has been shown to be associated with cleft lip and palate in animal models. However, rarely studies have linked SUMO1 to nonsyndromic cleft lip with or without cleft palate in humans. The purpose of this study was to confirm the contribution of SUMO1 to nonsyndromic orofacial clefts in western Han Chinese. Four single-nucleotide polymorphisms were investigated in 246 case trios in western China using conditional logistic regression, transmission disequilibrium test, and case-parent trio design. Strong evidence of linkage disequilibrium was found between these markers and the disease in both single-nucleotide polymorphism analysis (G allele at rs6761131 [p=0.0008, odds ratio (OR) = 1.92, 95% confidence interval (CI): 1.31-2.81], C allele at rs7580433 [p<0.0001, OR=2.79, 95% CI: 1.93-4.03], and G allele at rs10185956 [p=0.0069, OR=1.61, 95% CI: 1.14-2.27]) and haplotype analysis (A-C for rs6709162-rs7580433 [p=0.00024], C-G for rs7580433-rs10185956 [p=0.00091], and A-C-A for rs6709162-rs7580433-rs10185956 [p=0.004], among others). The risk factors identified in this study may provide a better understanding of the etiological role of SUMO1 in nonsyndromic cleft lip with or without cleft palate incidence.