Introduction: Increased long-term blood pressure variability (BPV), defined as monthly to yearly BPV, has been reported a risk factor of cardiovascular events independent of mean BP level. However, the relationship between long-term BPV and decrease in GFR remains unknown. In this study, we examined the association of Long-Term BPV and decrease in GFR. Methods: We included 214,443 type 2 diabetes mellitus patients with hypertension, registered in the Japan Diabetes Data Management Study Group, whose BP and HbA1c were simultaneously measured at least 4 times per year for 5 years from 2014-2018. BPV was defined as the 5-year coefficient of variation (CV), and the relationship between BPV and eGFR was examined. We also examined the relationship between BPV and the following background factors: (1) age (2) duration of diabetes (3) HbA1c (4) antihypertensive medications. The Ca-antagonist group was patients who took only Ca-antagonists during the 5-year period, and the ARB group was patients who took only ARBs. This study was a retrospective analysis. Data analyses were performed using the SPSS 28.0 software. Results: The group with greater 5-year BPV had lower eGFR than the group with smaller BPV, independent of mean BP (P<0.001). Regarding BPV and patient background, (1) BPV tended to increase with increasing age, and was significantly greater in patients over 50 years of age compared to those in their 30s (P<0.001). (2) The longer diabetic duration, the greater the BPV (P<0.001). Especially in patients more than 20 years’ diabetic duration, BPV was significantly larger than that of less than 5 years (P<0.001). (3) There was no association between HbA1c and BPV. (4) BPV was significantly lower in the Ca antagonist group compared with the ARB group over 5 years (0.069 vs. 0.078 P<0.001). Conclusion: Increased long-term BPV was observed older age and long duration of diabetes, but was not related to HbA1c. Interestingly, Patients with greater BPV had lower eGFR at 5 years. Disclosure M.Sakamoto: None. M.Yuki: None. K.Miyashita: None. T.Yamazaki: None.