ousepox is a serious infections disease of laboratory mice. It has been described as occurring in two forms , a rapidly fatal form, with few or nocutaneous lesions, and a chronic form, characterized by ulceration of the skin and particularly of the feet, tail and snout. Pathohistologically, the li-ver and the spleen contain numerous tissue necrotic areas different in degreeEosinophilic cytoplasmic inclusion bodies in groups which have clear bordercan be demonstrated in rash in the epidermal cells of the skin, eyelidsand the liver.By means of ABC dyeing and utilizing the antibody of poxvirusof mice, the position of the poxvirus of mice in the tissue can be diagnosed.Both in the rapidly fatal form and in the rapid period of the chronicform of the mousepox, the antibody of poxvirus of mice can be positive.