Aim To observe the change of large arterial compliance and carotid atherosclerosis,explore the correlation between them in prehypertensive people.Methods 300 subjects each with prehypertension,high and normal blood pressue were selected randomly,and brachial-ankle pulse wave velocity (BaPWV),ankle-brachial index (ABI),carotid arteries intima media thickness (IMT) and plaque were observed.Results (1)BaPWV accelerates as the blood pressure elevate,prehypertensive group(1 390±171 cm/s) increased than in the normal group(1 293±151 cm/s,P<0.01),lower than the hypertensive group((1 652±291 cm/s,P<0.01);ABI in prehypertensive group(1.115±0.060) compared with normal blood pressure(1.114±0.061) had no difference,lower than in hypertensive group (1.132±0.067,P<0.01).(2) IMT thickening and plaque rate in prehypertension group compared with normal blood pressure group showed no statistical difference,but lower than the hypertensive group (P<0.01).Carotid common arteries IMT (CCA-IMT) in prehypertension(0.73±0.10 mm)and normal blood pressure group(0.72±0.12 mm)had no statistical difference,which were significantly thickened in high blood pressure group(0.78±0.16 mm,P<0.01).(3)PWV in people with carotid plaque increased than normal controls,in each subgroup (P<0.01).BaPWV was positively related to CCA-IMT(r=0.271,P<0.01),after adjustment of blood pressure the correlation still exists(r=0.156,P<0.01).Conclusion In prehypertension,arterial stiffness indicator BaPWV significantly increased,suggesting the existence of