OBJECTIVE： To investigate the effects of tacrolimus （FK506） on peripheral blood cell immune function and liver lab index in liver transplant recipients different survival periods. METHODS： 27 liver transplant recipients receiving FK506 were selected and divided into group A （1 year≤ survival period＜5 years， 16 cases） and group B （5 years≤survival period≤12 years， 11 cases）. At the same time， 10 healthy volunteers were included into control group. Group A and B were given FK506 0.1-0.2 mg/kg， bid； control group didn’t received any treatment. Peripheral blood T leukomonocyte CD3+， CD3+CD4+， CD3+CD8+and CD4+/CD8+， B cell CD19+ and NK cell CD16+CD56+ level were compared among 3 groups. The levels of ALT， AST， ALB and GGT were investigated in 3 groups. RESULTS： The percentage of CD3+CD4+， CD19+ and CD4+/CD8+ ratio in group B were significantly lower than in group A and control group， and CD3+CD8+ was significantly higher than in group A and control group， with statistical significance （P＜0.005）； there was no statistical significance in CD3+， CD16+CD56+ in group B， compared to group A and control group （P＞0.05）. There was no statistical significance in above index between group A and control group （P＞0.05）.  The level of GGT in the group A and group B was higher than that in the control group. AST of group A was significantly higher than that of control group， and ALB of group B was significantly lower than control group， with statistical significance （P＜0.05）； there was no statistical significance in ALT， of group A and B， compared to control group （P＞0.05）； there was no statistical significance in the levels of ALT， AST， ALB and GGT between group A and group B （P＞0.05）. CONCLUSIONS： Immune function of liver transplant recipients with 5-12 years survival time was easily suppressed by FK506. CD3+CD4+， CD3+CD8+， CD4+/CD8+ level may serve as biomarkers to reflect the immune status of recipients and help to adjust the dose of FK506 timely and avoid the excessive immunosuppression.