Abstract: Abstaract Objective:By analyzing the results blood concentration monitoring of taking tacrolimus(FK506) in liver transplantation patients,to explore the factors affecting the tacrolimus blood concentrations. Methods: According to the ID of patients in the hospital, screening the patients undergoing liver transplantation in our hospital from 2010 to 2012, collecting the gender, age, the actual number of days in hospital, main diagnosis and other diagnosis and FK506 blood drug concentration and dose of the patients.Results: There are significant difference between the group within 14 days and 14 days later after liver transplantation, no difference between the blood drug concentration(p＜0.05); Gender has a certain effect on the plasma blood concentration of tacrolimus in the same time(p＜0.05); Within 14 days after transplantation, the dose of group A is less than group B and C, blood drug concentration in group C is less than group A and group B; In 14 days later after transplantation, the dose of group B more than group A and C, blood drug concentration in group C is less than group A and group B. Conclusion:There are many factors affecting the tacrolimus blood concentrations liver transplantation patients. The various factors of tacrolimus blood concentration should be taken into account in order to control the blood concentration in a ideal range, in favor of improving the survival rate of liver transplant patients.