Objective To investigate the effects of hyper-cardiovascular reactivity (HCVR) on circadian rhythm of ambulatory blood pressure and heart rate variability(HRV) in middle-aged male patients with essential hypertension (EH). Methods A total of 60 voluntary male EH patients were divided into EH+HCVR group (n=35) and EH+normal cardiovascular reactivity group (NCVR group, n=25) according to cold pressor test (CPT). Related clinic information, ambulatory blood pressure monitoring and HRV between the two groups were compared and analyzed. Results (1)The proportion of HCVR in 60 EH patients was higher than that in 50 normotensive controls (58.3% vs 26.0%; P＜0.01). (2)Compared with EH+NCVR group, the 24h average systolic blood pressure (SBP) [(148.9±8.9) vs (143.6±8.5) mmHg; P＜0.05] and 24 h diastolic blood pressure (DBP) [(94.4±5.7) vs (90.5±6.0) mmHg; P＜0.05], the average SBP [(145.4±9.2) vs (135.2±6.4) mmHg; P＜0.01] and DBP [(92.7±5.8) vs (83.6±5.2) mmHg; P＜0.01] of night in EH+HCVR group were higher, and the latter was more obviously increased; the circadian rhythm of ambulatory blood pressure lost, circadian rhythm of non-dipper in EH+HCVR group was higher than that in EH+NCVR group (74.3% vs 28.0%; P＜0.01). (3)The HRV index was lower in EH+HCVR group than in EH+NCVR group [SDNN: (85.8±10.7) vs (118.6±13.8)ms; SDANN: (73.1±14.2) vs (106.1±15.2)ms; RMSD: (14.3±5.5) vs (22.3±9.5)ms; PNN50: (4.9±2.1)% vs (7.0±3.0)%; P＜0.01]. (4)The logistic regression analysis indicated that HCVR (OR=4.53; 95%CI 1.77~11.60) and HRV (OR=10.28; 95%CI 3.94~26.86) decreasing were the risk factors of the loss of circadian rhythm in EH patients (P＜0.01). Conclusion The proportion of HCVR is higher in EH patients. Circadian rhythm of non-dipper, loss of circadian rhythm and HRV decrease are common in EH patients with HCVR and may be related with the autonomic nerve damage.