Abstract: EMG studies were made on 81 patients who had been diagnosed as progressive systemic Sclerosis (PSS) and considered to he associated with polymyositis (PM).We found 55 cases having abnormal EMG and 63 cages with elevation of muacie enzyme.EMG had positive correlation with clinical features and muscle enzymes (P<0.05,P<1.01),48/81 cases were considered suffering from a disease of progressiVe systemic sclerosis-polymyositis overlap syndrome.Diagnosis was based on the American Rheumatism Association (ARA) preliminary criteria for scleroderma and the criteria for PM/DM of Bohan and Peter.31 case were found to 6e increasingly improved,however not concurrently between EMG and CPK findings on follow up.There were dramatic decreasing of increased insertion irritability and polyphasic motor unit pottntials of short duration and small amplitude on EMG(P<0.01,P<0.05)

Key words: Scleroderma, systemic Polymyositis