Abstract: AIM To investigate the effect of obstructive sleep apnea hypopnee syndrome (OSAHS) on the blood pressure of young servicemen with first stage hypertension encamping on plateau for a short period and analyze the underlying mechanisms. METHODS Thirteen servicemen with hypertension were divided into two groups, 9 with OSAHS in OSAH group and 4 without OSAHS in control group. Blood pressure, peripheral blood oxygen saturation (SO2%), sleep time (h), apnea index (AHI) and neuroendocrine hormone (RAAS, cortisol) were collected at 10 d, 30 d and 60 d. RESULTS After stationing in the plateau region, systolic blood pressure and diastolic blood pressure in OSAHS group were significantly higher than the baseline (P<0.05), especially diastolic blood pressure. Blood oxygen saturation decreased significantly (P<0.05). Sleep time was significantly shorter (P<0.05), AHI significantly increased (P<0.05) and neuroendocrine hormone levels (renin-angiotensin-aldosterone system and cortisol) also increased (P<0.05). But no such significant differences were found in control group. CONCLUSION Encamping in plateau areas can lead to short-time exacerbation of hypertension. The mechanism may be related to OSAHS, which activates RAAS and stress hormone, resulting in more severe hypertension.