Today the statistical study on the edema of the tendon still remains in a state which requires further exploration. Therefore, by using a Mitamura's Abderhalden Dryer and Torsion-Balance, the author studied periodical changes of various edemas evoked by inflicting injuries to tendons, muscles, and skin of rabbits, and obtained the following results: 1. Of the Achilles tendon and long digital flexor tendon sutured groups, the edema both in the silk-thread group of the former and in the stainless-wire group of the latter was found to have reached its maximum stage around the end of the second week after operation, and it disappeared about the end of the sixth week. However, the degree of the edema is higher in the silkthread group than in the stainless-wire group. These findings coincide with microscopic ones. The normal water content of the Achilles tendon is about equal to that of the long digital flexor tendon when the Achilles tendon is severed. 2. Even in the case of severing the Achilles tendon, the edema reaches its maximum around the end of the second week after operation, and it practically disappears about the end of the sixth week. Likewise in the microscopic findings, the cellular substances are most abundant in the second week, showing an irregular inter-fiber spaces. These agree fairly well with the results obtained by Nakura and Takechi. 3. Changes of the edema evoked by pinching of the Achilles tendon, femur muscle, and femur skin take a similar course. The edema caused by the pinching of the musele and skin occurs more rapidly than that by the pinching of the tendon, especially markedly up to 24 hours after operation. 4. In comparing the degrees of the edema, it is highest in the case of pinching the femur muscle, followed by the pinching of the Achilles tendon → in the Achilles tendon sutured with silk thread → the severed part of the Achilles tendon → in the long digital flexor tendon sutured with stainless wire, in the order mentioned.