Objective To assess the influencing factors of interdialysis blood pressure variability (BPV) in maintenance hemodialysis (MHD) patients from Pearl River Delta,and provide clinically useful information for the prevention and treatment of BPV.Methods MHD patients in 10 hemodialysis centers from Pearl River Delta were enrolled and analyzed retrospectively.According to the quartile of interdialysis systolic blood pressure-coefficient of variation (SBP-CV),patients were divided into four groups,and clinical data,biochemical indicators and drug use were compared among 4 groups.Binary logistic regression analysis was used to analyze the associated factors of interdialysis BPV.Results A total of 1010 MHD patients (612 males and 398 females) with the age of (56.3±13.9) years were enrolled in this study.Their dialysis duration was (48.4±36.1) months,and the median of interdialysis SBP-CV was 8.07％ (5.72％,11.34％).According to the quartile of SBP-CV,the patients were divided into four groups:low BPV group (SBP-CV≤5.72％,253 cases),middle BPV group (5.72％ ＜ SBP-CV≤8.07％,252 cases),high BPV group (8.07％ ＜ SBP-CV≤11.34％,253 cases) and extremely high BPV group (SBP-CV ＞ 11.34％,252 cases),and the dialysis duration,diabetes,ultrafiltration,interdialysis weight gain rate (IDWGR),serum calcium and the proportion of calcium channel antagonist used in the 4 groups were significantly different (all P ＜ 0.05).Logistic multiple regression analysis showed that high IDWGR (OR=1.216,95％CI 1.108-1.435,P ＜ 0.001) was an independent risk factors for interdialysis BPV in MHD patients,while high ultrafiltration volume (OR=0.436,95％CI 0.330-0.575,P ＜ 0.001) and calcium channel antagonists used (OR=0.686,95％CI 0.477-0.986,P=0.042) were independent protective factors.Conclusion High IDWGR is an independent risk factor for interdialysis BPV in MHD patients,while high ultrafiltration volume and calcium channel antagonists used are protective factors for interdialysis BPV in MHD patients.