Abstract: Objective To observe the effect of different exercise intervention methods on autonomic nervous system（ANS） in patients with essential hypertension（EH）. Methods A randomized controlled trial was designed. In March 2022,102 patients with grade 1 and 2 EH from Beijing Xiluoyuan Community Service Center and Shandong Zibo Wanjie Rehabilitation Hospital were recruited and randomly divided into Tai Chi group（n=34）, fitness exercises group（n=34） and control group（n=34） in a 1∶1∶1 ratio. Patients in Tai Chi group and fitness exercises group respectively received 60 minutes of Tai Chi and fitness exercise training three times a week for 12 weeks, with exercise intensity controlled at 40%-60% reserve heart rate. Patients in the control group did not receive any exercise intervention. The changes of blood pressure variability（BPV） and heart rate variability（HRV） of patients before and after the intervention in the three groups were observed. Results Finally 80 participants completed all experimental procedures and were included in the analysis（28 in Tai Chi group, 30 in fitness exercises group, and 22 in control group）. In the Tai Chi group, BPV indicators such as standard deviation of 24-hour systolic blood pressure（24hSBPSD）, coefficient of variation of 24-hour systolic blood pressure（24hSBPCV）, standard deviation of 24-hour diastolic blood pressure（24hDBPSD）, and coefficient of variation of 24-hour diastolic blood pressure（24hDBPCV） decreased（P＜0.01）, while HRV indicators such as standard diviation of normal to normal RR intervals（SDNN）, root mean square of successive differences（RMSSD）, low frequency（LF）, high frequency（HF）, total power（TP）, standard deviation of instantaneous variability of the beat-to-beat heart rate（SD1）, and standard deviation of long-term continuous RR interval variability（SD2） increased（P＜0.05） after intervention compared with before intervention, and the proportion of successive RR intervals differences＞50 ms in relation to the total RR intervals（pNN50） and LF/HF showed no significant changes（P＞0.05）. In fitness exercises group, BPV indicators such as 24hSBPSD, 24hSBPCV, 24hDBPSD, and 24hDBPCV decreased（P＜0.05）, while HRV indicators such as SDNN, RMSSD, pNN50, LF, HF, TP, SD1 and SD2 increased（P＜0.05）, and LF/HF showed no significant change（P＞0.05） after intervention compared with before intervention. There was no significant change in indicators of BPV and HRV after intervention in control group（P＞0.05）. After intervention, compared with control group, 24hSBPSD, 24hDBPSD and 24hDBPCV were lower（P＜0.05）, while SDNN, RMSSD, LF, TP, SD2 and SD1 were higher（P＜0.05） in Tai Chi group, 24hSBPSD, 24hDBPSD, and 24hDBPCV were lower（P＜0.05）, while SDNN, RMSSD, pNN50, LF, HF, TP, SD1 and SD2 were higher（P＜0.05） in fitness exercises group. Compared with fitness exercises group, there was no significant difference in indicators of BPV and HRV after intervention in Tai Chi group（P＞0.05）. Conclusions Tai Chi and fitness exercises can effectively reduce BPV and increase HRV in EH patients. Two types of exercise have positive effects on improving ANS function in EH patients.