Objective To explore the safety and effectiveness of Shenkang Injection (SI) for con- trast-induced nephropathy (CIN) in elderly patients with chronic kidney disease (CKD). Methods Totally 206 elderly CKD patients who were scheduled to undergo coronary angiography (CAG) were assigned to three groups according to random digit table, i.e., the rehydration therapy group (67 cases) , the SI group (71 cases) , and the control group (68 cases). Patients in the rehydration therapy group received intrave- nous dripping of normal saline 12 h before and after CAG. Patients in the SI group received intravenous drip- ping of SI, while those in the control group received intravenous dripping of 5% glucose injection. SI and 5% glucose injection was respectively used 3 days before CAG and 4 days after CAG, once per day. The inci- dence rate of CIN, and levels of creatinine, blood urea nitrogen (BUN) , serum cystatin C (CysC), kidney injury molecule-1 (KIM-1), and P2-microglobulin (P2-MG) were detected before CAG, 24 h and 96 h after CAG, respectively. Age, sex, SI, contrast dose, pre-CAG indicators of renal function were compared. Their correlations with changed 24-h creatinine value (the difference between the value at post-CAG 24 h and pre-CAG) and CIN incidence rate were analyzed using Sperman correlation and Logistic regression analy- ses. Results Compared with the rehydration therapy group and the control group, the incidence rate of CIN was significantly lower in the SI group (x2 = 5. 32, P <0. 05). Compared with before treatment in the same group, levels of creatinine and CysC were all elevated in the 3 groups after 24-and 96-h treatment (P <0. 05) ; the KIM-1 level increased in rehydration therapy group and the control group (P <0. 05) ; P2-MG level increased in the SI group (P <0.05). Compared with the control group, post-CAG P2-MG level in- creased in the SI group (P <0. 05). There was no statistical difference in other index (P >0. 05). SI was neg- atively with the incidence rate of CIN and changed 24-h creatinine value (r = -0. 612, -0. 517, P <0. 05). The contrast dose was positively with the incidence rate of CIN and changed 24-h creatinine value (r = 0. 644, 0. 562, P <0. 05). Increased contrast dose could elevate the incidence rate of CIN (P <0. 05). SI could obviously lower the incidence rate of CIN (P <0. 05). Conclusion SI could lower the incidence rate of CIN in elder CKD patients by playing certain roles in prevention and treatment.