Abstract: In 12 cases of lupus erythematosus, including 6 cases of systemic lupus erythematosus (SLE), 4 cases of discoid lupus erythematosus (DLE) and 2 cases of subacute cutaneoits lupus erythematosus (SOLE), infiltrating cells of cutaneous lesions were examined using monoclonal antibodies with a peroxidase anti-peroxidase method. It was found that in the infiltrating mononuclear cells, 50~80% cells reacted with Leu4. The percentage of Leu3a and Lcu2a positive cells were 10~60% with approximately equal numbers.