To study the interactive effect of job stress and genetic susceptibility (or gene polymorphism) on hypertension. A cross-sectional epidemiological study was conducted in 452 workers from a thermal power plant in China. Extrinsic effort, occupational reward, and over-commitment were measured. Hypertensive patients were defined by three phases of screening, reexamination, and final diagnosis. β 2 -AR genotypes and allele frequencies at amino acid positions 16 (β 2 -AR-16: Arg→Gly) and 27 (β 2 -AR-27: Gln→Glu) were identified by PCR-RFLP. Job stress was related with the prevalence of hypertension in males (P<0.05), whereas no significant relationship was found in females (P>0.05). Differences in genotypes and allele frequencies of the β 2 -AR-16 were statistically significant between the hypertension and control groups (P<0.05), whereas those of β 2 -AR-27 were not (P>0.05). The prevalence of hypertension was higher in individuals carrying Gly16 allele than in those carrying Arg16 allele of the high job stress group (P<0.01 or 0.05). High job stress and polymorphism of β 2 -AR-16 have an interactive effect on the prevalence of hypertension in male workers.