Chronic kidney disease (CKD) patients are proved at high mortality risk,especially when combined with secondary hyperparathyroidism(SHPT). It’s revealed that the occurrence of death in hemodialysis patients had circadian rhythm, with highest incidence during night and early morning. Under physiological conditions, heart rate (HR) experience a 10-20% decrease and reach their nadir at night and then increase steeply in the early morning. However, much less is known about the predictive power of ambulatory HR for all-cause mortality in CKD patients. Besides, the treatment value of parathyroidectomy(PTX) for 24 hour HR indexes in severe SHPT patients is also uncertain. The cross-sectional study included 162 controls and 502 stage 5 CKD patients, including PTX (n=316) and non-PTX (n=186) subgroups. We explored the associations of clinical characteristics and 24 hour HR indexes in CKD patients using multivariable regression analysis. HR in each hour were measured by 24 hour Holter. Non-dipping HR was defined as a night/day HR ratio > 0.90. Then we analyzed the effects of PTX on severe SHPT patients (n=50) with short-term follow-up(median intervals:6.3months). A long-term follow-up (median intervals:46.0months) was performed to investigate whether 24 hour HR indexes predicted all-cause mortality using multivariable Cox regression model. We last identified the long term treatment value of PTX in severe SHPT patients(n=300) from the perspective of chronobiology. The demographic and clinical characteristics in controls and stage 5 CKD patients were showed in Table 1. Multivariable linear regression models proved that CKD patients had higher 24 hour, daytime, nighttime mean HR and night/day HR ratio compared with controls. In multivariable analysis, the night/day HR ratio was positively associated with age, systolic blood pressure, serum intact parathyroid hormone(iPTH) level and negatively associated with serum albumin level. CKD patients had 24 hour HR profile that fluctuated less than controls, especially in PTX group. After successful PTX in severe SHPT patients, the night/day HR ratio was reversed from (0.93±0.06) to (0.88 ± 0.08) (P<0.001), and 24 hour, daytime, nighttime mean HR were significantly decreased(Fig. 1). In long-term follow-up study,there were 60 deaths in 482 CKD patients with the missing rate of 3.98%. Night/day HR ratio, instead of 24 hour, daytime and nighttime mean HR, predicted all-cause mortality in CKD patients. Higher survival probabilities were observed in PTX than non-PTX group with Kaplan-Meier curve (Fig. 2A). The survival probabilities in non-PTX patients were significantly related to the tertiles of night/day HR ratio (Fig. 2B), while there was no significant difference in PTX group (Fig. 2C). In stage 5 CKD patients we provided new information on the prevalence and clinical significance of non-dipping 24 hour ambulatory HR pattern, which predicted higher all-cause mortality. PTX could reverse non-dipping HR ratio and improve survival rate in severe SHPT patients. Circadian rhythm abnormalities of HR are suggested to be treated effectively in order to improve prognosis in CKD. Mechanisms behind the adverse prognostic value of a blunted ambulatory HR rhythm remain to be elucidated.