Abstract: This paper presents 72 cases of occupational melanosis seen in the period 1972-1981. Investigation in the factory showed a morbidity of 2.04%. Statistical attalysis had been made according to the occupation, kind of work, causative agents, sex, age and clinical manifestations of the patients.This paper discussed the relation between serum level of copper and the formation of pigment and hydrocarbons (such as gasoline etc) and the onset of the disease. A preliminary discussion on the prevention of the disease had also been touched upon. According to the clinical manifestations of the patients, the disease could be classified into four types. The cure rate was 57%.the rate of marked improvement was 22.2%.The cure rate of those who remained at their original post was considerablp different, from those who were removed from their original post although the treatment was the same in the two groups of patients.There were 8 patients who returned to their original post after recovery got relapsed or worse.