The purpose of this stud is to evaluate the prevalence of hypertensive disease among different occupational groups. After probabilities proportional to size sampling, 1422 students and 2737 their parents were included in this study. Occupational history, history and risk factors of hypertensive diseases were collected by questionnaires. From this study,the non-skilled, manual male workers (lowest social class group) had the highest prevalence of hypertension. Occupational factors such as work strain, physical activity at work and non- occupational factors such as lifestyles contributed to these differences. After controlling for the influences of non-occupational factors, the prevalence of hypertension in the lowest social class male workers was higher than the highest subjects.