The change of acid-phosphatase in Fuji apples Was investigated in terms of storage temperature and pressure. The firmness, sugar contents, acidity and activity of acid-phosphatase with electrophoretic pattern were studied during storage. The firmness, sugar contents and acidity were decreased during storage. Ratio of decrease was greater at normal temperature than low temperature and normal atmosphere than sub-atmosphere. Acid phosphatase activity of apples was mainly existed cell wall fraction and increased with climacteric rise and decreased later. The activity was higher at normal temperature than low temperature and at atmosphere than sub-atmosphere. The optimal temperature and pH were $45^{circ}C$ and pH 5.6, respectively. In stability of heat and pH, enzyme solution was stabilized to $30^{circ}C$ and pH 5-8. Electrophoretic pattern of enzyme solution extracted from sub-atmospheric pressure with low temperature and normal atmospheric pressure with normal temperature yielded two activity bands during storage.