Abstract: Objective To investigate the correlation between blood concentrations of tacrolimus (FK506) and cystatin C (Cys C) and the effect of FK506 on glycolipid metabolism in renal transplant recipients. Methods A total of 325 patients receiving renal transplantation between August, 2014 and September, 2015 in Nanfang Hospital were divided into 4 groups according to the postoperative time (1 month group, 1-3 months group, 4-6 months group, and 7-12 months group). FK506 blood trough concentration was measured at the time of postoperative follow-up, and creatinine (Scr) and Cys C levels were also detected. Results Plasma FK506 concentration decreased with age in the recipients and showed a positive correlation with Cys C (r= 0.985, P=0.015) but no obvious correlation with Scr (r=0.259, P=0.741). FK506 had no effect on blood glucose (5.53-5.59 mmol/L) or blood lipids (TG 1.47-1.55 mmol/L, TC 5.04-5.17 mmol/L, LDL-C 3.00-3.07 mmol/L, and VLDL 0.73-0.76 mmol/L) in patients 1-6 months after renal transplantation. Conclusion FK506 does not affect the level of glycolipid metabolism in patients after renal transplantation. Cys C is positively related to blood concentration of FK506 in the renal transplantation recipients. The rational use of FK506 can improve the effectiveness and safety of the treatment in the recipients.