〔Abstract〕 Objective To investigate the relationship between the 24 h ambulatory blood pressure circadian rhythm abnormalities and kidney damage in the patients of lupus nephritis(LN). Methods A total of 103 patients with LN patients were enrolled retrospectively. All patients were accepted 24 h ambulatory blood pressure monitoring(ABPM). The patients were divided into 2 groups according to the 24 h ambulatory blood pressure circadian rhythm, including nocturnal blood pressure meaning average declining during the day(>10%) and non-dipper type blood pressure group(<10%). The kidney damage index of LN patients with or without hypertension or noc-turnal blood pressure and non-dipper type blood pressure was analyzed. The influencing factors of the circadianrhythm of LN blood pressure were analyzed by binary Logistic regression.Results Among the 103 LN patients, 66patients were hypertension, 37 patients were none hypertension. Fifty-nine patients were non-dipper type bloodpressure in LN with hypertension group, and 30 patients were non-dipper type blood pressure in LN without hyper-tension. There was no significant difference in the frequency of non-dipper type blood pressure between the twogroups(81. 1%vs89. 4%, χ2= 1. 395,P= 0. 238). Compared with hypertension group, the levels of serum cre-atinine(Z= 2. 911,P= 0. 004), urea(Z= 3. 348,P= 0. 001) and uric acid levels(t= 2. 017,P= 0. 047)were significantly higher than those of LN without hypertension patients, whereas the levels of glomerular filtrationrate(eGFR)(Z= 4. 846,P<0. 001) were significantly lower than those of LN without hypertension patients. Inthe group of LN with hypertension, the levels of uric acid(Z= 2. 893,P= 0. 004) were significantly higher thanthose of nocturnal blood pressure subgroup patients compared with no dipper type blood pressure subgroup patients,and the levels of eGFR(Z= 2. 017,P= 0. 0440) were significantly lower. Nevertheless, in the group of LN with-out hypertension, the kidney damage index had no significant difference between the two subgroups. Univariate andmultivariate analysis showed that uric acid was associated with an abnormal rhythm of LN combined with hyperten-sion.Conclusion Abnormal blood pressure rhythms are common in LN patients with or without hypertension. Re-nal damage significantly increases in the non-dipper group of LN compared with hypertension patients.