Our study was to investigate the factors relating to thecoronary slow flow phenomenon (CSFP) and to observe thechanges of Cystatin C (CysC) level in patients with coronaryslow flow phenomenon (CSFP) and clinical predictive value.The CysC levels were examined. The data of patients withcoronary angiography were collected. The proportion of malein the CFSP group was significantly higher than the othertwo groups (p<0.05). The age and creatinine level weresignificantly lower than the other two groups (p<0.05). Thelevel of cystatin C, uric acid and proportion of smokinghistory in patients with CSFP was higher than that in normalgroup and lower than that in mild stenosis group (p<0.05).Cystatin C was an independent risk factor for CSFP (OR>1),while uric acid and history of smoking are not... related toCSFP. In the CSFP group, LAD, LCX and appears RCA were75.36%, 68.12% and 23.91%, respectively. There were nosignificant differences in gender, age, cystatin C, UA,CREA, UREA, and smoking history among the different vesselsin the CSFP group (P>0.05). Serum cystatin C level isassociated with the occurrence and development of CSFP, andit can be the predictor of CSFP.