Abstract: Objective To study the effects of plasma renin activity and aldosterone level on blood pressure variability in white coat hypertension (WCH). Methods A total of 150 patients with WCH, 161 patients with mild to moderate essential hypertension (EHT), 167 cases of normotension group (NTG) were chosen from outpatient department or inpatient department from January, 2013 to December, 2016. Ambulatory blood pressure, plasma renin activity (PRA) and aldosterone (ALDO) were monitored in each group. Results Pearson correlation analysis showed that All day systolic blood pressure standard deviation (ADSSD, r=0.644), and All day diastolic blood pressure standard deviation (ADDSD, r=0.707) in WCH group were positively correlated with PRA (all P<0.001). ADDSD(r=0.861) was positively correlated with ALDO (P<0.001). The correlation between ADSSD (r=0.308) and ALDO was not statistically significant (P=0.072); the correlations between ADSSD (r=0.125, -0.167), ADDSD (r=0.036, -0.265) and PRA in EHT and NTG group were not statistically significant (P=0.560, 0.338, 0.794, 0.124). The correlations between ADSSD (r=-0.027, -0.024), ADDSD (r=0.009, 0.012) and ALDO in EHT and NTG group were not statistically significant (P=0.860, 0.890, 0.956, 0.920). Conclusion Blood pressure variability in patients with WCH is associated with PRA.