Objective 1.To explore the role of environmental factors in the development and maintenance of hypertension . 2. To establish a hypertensive model without surgical or phar macologic intervention. 　Methods One hundreds male, 2-3-month-old Wistar rats were rand omly divided i nto 4 groups: 1. Cold-treated group(C, n=28): animals were exposed to cold (4±2)℃ for 4 hours per day for 8 weeks; 2. High salt-treated group (S, n=28): animals were given 8% NaCl di ets for 8 weeks. 3. Cold combined high salt-treated group (CS, n=28). Animals were given 8% N aCl diets for 8 weeks besides cold exposure. 4. Control group (N, n=16). Systolic blood pressur e(SBP, Tail-cuff technique) and heart rate were measured weekly in 4 groups throughout the experi ment. The thoracic aortas were extracted for morphologic studies. 　Results On the end of the first week, the average SBP and heart r ate of C, S, and CS group were sighificantly increased (P<0.01) than that of the N group. Blood pressure reached a maximal level by 3 weeks in C, S, and CS group (127.0±6.0, 125.9±5.5, 131±6.0)mmHg, respect ively, SBP remained significantly elevated for the remaining of the experiment. 　Conclusion Cold circumstance and high-salt intake play an impo rtant role in the development of hypertension. This model appears to be a successful model for the induction of hypertension in rats without surgical intervention or excessive doses of hormones.