The present study aimed to explore gene-gene and gene-environment interactions among three candidate genes and several environmental risk factors, and their impacts on hypertension in Chinese Mongolian population. A cross-sectional study was conducted in 2003-2004 among 1,575 Mongolian people in Tongliao City of Inner Mongolia, China. Epidemiologic and clinical data and blood samples were obtained from subjects. Multifactor dimensionality reduction (MDR) and logistic regression were used to analyze gene-gene and gene-environment interactions. The MDR model indicated a significant interactions among the CYP11B2 gene C(-344)T polymorphism, body mass index, age, and alcohol consumption on the risk of hypertension, with a cross-validation consistency of 10 of 10 and a prediction error of 34% (P < 0.001). Logistic regression suggested alcohol consumption (≥200 g/d) was associated with an OR of 2.4 (95% CI, 1.6-3.5) for hypertension. When stratified by the CYP11B2 genotype, the estimated OR was 1.2 (95% CI, 0.5-3.0) on hypertension for the CC genotype group, but was 3.0 (95% CI, 1.5-5.7) and 2.9 (95% CI, 1.4-5.7) for the TC and TT genotype groups, respectively. A significant interaction between the CYP11B2 genotype and alcohol consumption was also found by the logistic models (P (crude) = 0.035, P (adjusted) = 0.048). This study demonstrates a significant interaction between the CYP11B2 genotype and alcohol consumption on the risk of hypertension in Chinese Mongolian population.