We studied the difference of the enzymatic activity

including Succinic dehyd-rogenase(SDH)

a-Naphthol acetate esterase (ANAE)and Peroxidase(PO)

and the ratio of phagocytic chicken red blood cells in the adherent and cultured humanmononuclear phagocytes. The results showed; the enzymatic activity of SDH andANAE in adherent ’cells were stronger than tne nonadherent cells before the cellswere cultured (P<0.01 and 0.05) . When the adherent cells had been cultured for 24/48 hours

the difference of the enzymatic activity between the still adhered cells and detached cells did not have any statistic significance. The PO activity of the adherent cells and detached cells cultured 48 hours were lower than the same cells cultured 24 hours (P<0.01) . The difference of the ratio of phagocytic chicken red blood cells had not shown any statistic significance among the cell groups described above. It indicates that when there was no the stimulation of human serum

the difference of adherent capacity in mononuclear phagocytes seems to be responsible to the condition of their differentiation and maturation or their functional activation.