This experiment was performed to investigate the response of inorganic substances in alveolar bone in relation to the experimental tooth movement. Right canine in maxillary jaw was tipped in cats by coil springs generating 80 gm. force, in mandibular jaw, the force was 100 gm. force. Cats were divided into five groups and orthodontically treated for one hour, 1, 7, 14 and 28 days, respectively. Alveolar bone samples were obtained from tension and compression sites as well as from contralateral control * es. The level of calcium of alveolar bone was determined by atomic absorption spectrophotometry and inorganic phosphorus was measured by spectrophotometry. The results obtained were-as follows: 1. In tension and compression site of maxillary alveolar bone, calcium levels were decreased at 1, 7 and 14 days, but recovered at 28 days. 2. The levels of inorganic phosphorus in compression site of maxillary alveolar bone had little change but in tension site of maxillary alveolar bone,, phosphorous levels were decreased. 3. Calcium levels in tension and compression site of mandibular alveolar bone were decreased, especially at 28 days. 4. In tension and compression site of mandibular alveolar bone, inorganic phosphorus were slightly decreased from I day.