Objective：This study aims to observe the efficacy of dapagliflozin on patients with early diabetic kidney disease(DKD) and the influence on expression of regulatory T cells(Tregs)and inflammatory factors. Methods：Forty-seven patients who developed DKD between August 2019 and December 2019 in the Affiliated Jiangning Hospital of Nanjing Medical University were enrolled. On the basis of the original hypoglycemic therapy，all patients were prescribed dapagliflozin 10 mg，qd，orally，for 4 weeks and kept diet and exercise mode unchanged. Fasting plasma glucose(FBG)，glycated albumin(GA)，urinary albumin creatinine ratio(UACR)，24-hour urinary protein and estimated glomerular filtration rate(eGFR)were compared between baseline and 4-week after prescription. The level of Tregs in peripheral blood detected by flow cytometry，the levels of interleukin(IL)-6，IL-1β，tumor necrosis factor(TNF)-β and IL-10 measured by ELISA were also compared. Adverse drug reactions were recorded. Results：After 4 weeks of dapagliflozin treatment，FBG[(8.96 ± 0.83 mmol/L)^vs.(7.42 ± 0.67)mmol/L]，GA[(18.47 ± 3.32)% vs.(15.49 ± 2.62)%]，24 h urine protein quantification [1.14(0.29，2.08)g/24 h vs .0.28(0.15，0.83)g/24 h]，UACR[80(45，150)mg/g vs. 40(30，80)mg/g]and eGFR[(105.30 ± 36.01) mL/(min·1.73 m² )vs.(92.07 ± 35.26)mL/(min·1.73 m² )]were significantly lower than baseline(P ＜ 0.05). However，after 8 weeks of treatment，the eGFR could return to the level before treatment[(104.88 ± 36.86)mL/(min · 1.73 m² )vs.(105.30 ± 36.01) mL/(min·1.73 m² )，P ＞ 0.05]. Compared with baseline，the expression of Tregs was significantly up-regulated[(3.19 ± 0.74)% vs. (5.64 ± 0.93)%，P ＜ 0.05]，the pro-inflammatory factors IL-1β[(7.83 ± 1.39)ng/L vs.(4.57 ± 0.71)ng/L]，TNF-β[(372.85 ± 6.79) ng/L vs.(227.62 ± 7.29)ng/L]，IL-6[(3.99 ± 0.47)ng/L vs.(2.59 ± 1.01)ng/L]was significantly down-regulated(P ＜ 0.05)，and the expression of the anti-inflammatory factor IL-10 was up-regulated[(0.03 ± 0.01)ng/mL vs.(0.05 ± 0.01)ng/mL，P ＜ 0.05]. There were no adverse reactions such as hypoglycemia and ketosis，and 5 patients had asymptomatic urinary tract infection during the treatment period. Conclusion：Dapagliflozin may up-regulate the expression of Tregs to inhibit the inflammatory response and ultimately play a role in renal protection in DKD patients.