Objective: To investigate the effects of milrinone on levels of inflammatory factors and liver and renal function after CPB in rheumatic heart disease patients for valve replacement. Methods: From January 2014 to January 2016, 80 patients received valve replacement in the Central Hospital of Chongqing Three Gorges were randomly divided into observation group and control group by block randomization grouping method, with 40 patients in each group.The patients in the observation group were pumped intravenously with milrinone 0.5μg·kg^-1·min^-1 for 72h after surgery, while the patients in the control group were not pumped.The serum levels of IL-6, IL-8, IL-10, TNF-α were detected by ELISA before operation and on 0d, 1d, 3d, 5d after operation, respectively.The levels of ALT, AST, Scr were also detected at the same time.Moreover, the time for operation, extracorporeal circulation, interruption, mechanical ventilation, ICU and hospital were also compared between the two groups. Results: The levels of TNF-α, IL-6, IL-8 and IL-10 increased immediately after operation in both groups[control group: (14.97±5.14)pg/mL, (52.45±10.37)pg/mL, (34.10±8.38)pg/mL, (32.27±8.45)pg/mL; observation group: (16.05±5.71)pg/mL, (54.39±8.56)pg/mL, (33.80±7.69)pg/mL, (31.48±5.94)pg/mL, t=-0.628, -0.644, 0.116, 0.342], and the peak values of TNF-α, IL-6 and IL-8 reached on the first day after operation in both two groups[control group: (52.07±10.18)pg/mL, (96.04±26.45)pg/mL, (91.14±18.28)pg/mL, (48.10±9.78)pg/mL; observation group: (50.37±12.98)pg/mL, (93.66±24.10)pg/mL, (83.16±16.28)pg/mL, (46.68±9.25)pg/mL, t=0.559, 0.295, 1.458, 0.473], and the peak value of IL-10 reached on the 3rd day after operation(t=-3.577), the differences were statistically significant on the 3rd day after operation[control group: (36.03±9.39)pg/mL, (59.56±14.38)pg/mL, (53.91±13.16)pg/mL, (85.55±16.49)pg/mL; observation group: (36.70±4.33)pg/mL, (36.20±3.85)pg/mL, (42.91±7.30)pg/mL, (101.33±10.81)pg/mL, t=-0.289, 7.017, 3.267, -3.577]. The levels of ALT, AST and Scr increased immediately after operation in both groups[control group: (38.51±5.12)U/L, (40.23±5.03)U/L, (62.27±5.02)μmol/L; observation group: (39.20±4.67)U/L, (39.6±4.94)U/L, (73.61±4.04)μmol/L, t=0.114, 0.243, 0.630], there were tatistically significant difference between the two groups on the 5th day after operation[control group: (61.45±5.27)U/L, (54.20±7.0)U/L, (86.45±9.01)μmol/L; observation group: (36.20±3.85)U/L, (34.85±7.12)U/L, (83.7±11.07)μmol/L, t=11.231, 9.224, 5.647], and on the fifth day, the levels of ALT, AST and Scr in the observation group dropped to normal, while only the level of Scr in the control group dropped to normal.There were no statistically significant differences in the time of operation, extracorporeal circulation, interruption, mechanical ventilation between two groups (t=0.267, 0.151, 0.187, 0.773, all P>0.05). However, there were statistically significant differences in the time of ICU and hospital [control group: (54.90±16.84)h, (14.35±3.01)d, observation group: (44.05±7.06)h, (10±1.86)d, t=8.149, 13.042, all P<0.05]. Conclusion Milrinone can obviously improve the inflammatory reaction in surgical trauma tissues caused by IL-6, IL-8, IL-10, TNF-α, and can protect liver, renal tissue from injury, moreover, it can decrease the incidence of postoperative complications and the length of hospital stay.