Objective     To investigate the lymphocyte immunophenotype in liver allograft and analyze the relationship between complications and the distribution or quantity of different lymphocytes.      Methods     Liver allograft specimens for biopsy were immunocytochemically stained for CD8

CD4

CD3

CD20

CD45RO and CD45RA. Lymphocyte immunophenotype was analyzed in different regions based on the liver morphology.      Results     T

otally 108 specimens were collected

62 diagnosed as acute cellular rejection (ACR group) and 46 as other complications (non-ACR group). CD3

+

cells

CD8

+

cells and CD20

+

cells of ACR group were significantly more than those of non-ACR group in portal tract (

P

<

0.01)

but not significantly different in lobule (

P

>0.05). In ACR group

CD8

+

cells were significantly more than CD4

+

cells in both portal tract and lobule (

P

<

0.05). CD8

+

cells

CD3

+

cells and CD45RO

+

cells infiltrated ducts or vessels in ACR Group more easily than those in nonACR group (

P

<

0.01). The amount of CD8

+

cells and CD45RO

+

cells was related to the degree of ACR.      Conclusion     The lymphocyte immunophenotype detection in liver allograft specimens is helpful in pathologic diagnosis and differential diagnosis of acute cellular rejection.