To observe the surface microstructure features by using scanning electron microscope , and study the surface antigen on lymphocytes of Paralichthys oliveaceus by form rosette with sheep red bloods cells and the cross-reactivity by using monoclonal antibody against human CD .Under scanning microscope , there are two kinds of lymphocytes , type I lymphocytes is characterized with being full of bumpiness and holes , the surface of type II lymphocytes is rather smooth with tiny finger like tubercle .The rosette formation of lymphocytes with sheep red blood cells is obvious however the rosette forming percents of lymphocytes is rather low, lower than 2 %.The cross reactivity of lymphocytes with monoclonal antibody against human CD showed that there are 5 .25 % 0 .38 % of NK cells in peripherial lymphocytes of Paralichthys oliveaceus , and the CD25 percentage of lymphocytes is 5 .25 % 0 .38 %.No cross-reactivity with T-cell antigen ,B-cell antigen and other activity antigen is found on the lymphocytes surface of Paralichthys oliveaceus .