Objective To investigate the change in natural kill cell,T-ly mphocyte subset counts and effect of recovery after homologous and autologous blood transfusion.Methods 50 patients undergoing lung cancer operation were randomly divided into two groups:group A received autologous blood transfusion with 400ml and group H received homologous blood transfusion with 400ml.Venous blood samples were taken before surgery,before blood transfusion and on the 1st and 5th postoperative day for determination of T-ly mphocyte subsets and natural kill cell counts by flow cytomet.The existent ratio of 1～3 years were followed up.Results The NK cell,CD+_3 and CD+_4 counts and CD+_4/CD+_8 ratio decreased significantly on the 1st postoperative day in both groups(P