Abstract: Objective To investigate the relationship among long-term alcohol drinking and dehydrogenase 2 (ADH2), aldehyde dehydrogenase 2 (ALDH2) gene polymorphism for the susceptibility of obstructive sleep apnea hypopnea syndrome(OSAHS). Methods From February 2014 to February 2017, 321 pat ients with snoring were studied, a ll patients underwent overnight sleep monitoring，and there were OSAHS group(208 cases )and non-OSAHS group( 113 cases ) according to the apnea-hypopnea index(AHI)．Investigate the drinking history of all subjects, mean monthly alcohol consumption and cumulative alcohol consumption were calculated， the relationship between alcohol ingestion and OSAHS were analyzed.The polymorphisms of ADH2 Arg47His and ALDH2 Glu487Lys were detected by polymerase chain reaction-ligase detection reaction (PCR-LDR) methods, the relationship between gene polymorphism and OSAHS were analyzed ．Results The alcohol consumption rate was 42.80% in OSAHS group, 38.41% in non-OSAHS group, and no statistically significant difference between the two groups (P>0.05). Patients with heavy alcohol consumption were 2.310 times mor e likely to have OSAHS than non-drinkers(95％CI：1.364-1.967，P=0.013). Heavy alcohol drinkers had a more percentage of total sleep time(TST)spent with saturation of oxyhemoglobin(Sa02)<90％and lower average SaO2. The frequency of ADH2 genotype AA/ （AG+GG） and ALDH2 genotype GG/(GA+AA) in OSAHS group had no statistical differences comparing with the control group(P>0.05) ．Compared with ADH2 genotype AA and ALDH2 genotype GG, other genotypes did not increase the risk of developing the OSAHS. Conclusion Heavy alcohol consumption is associated with a significantly increased risk of OSAHS and it exacerbates nocturnal hypoxia in OSAHS patients. Genetic polymorphisms of ADH2, ALDH2 are not related to the development of OSAHS.