Partial closure of an epiphyseal plate can reduce growth in length and cause angular deformationof the bone. The bone bridge between the epiphysis and the metaphysis, which inhibits growth, can be removed operatively, leaving a cavity, and improvement of the deformity by normal growth is then possible. Previous study have shown that silastic or bone cement diminished both the angular deformity and growth retardation to a highly significant degree. In the present study we wanted to test whether indomethacin and iliac apophysis as an interposition material could prevent bone bridge recurrence following operative removal in adolescent rabbits. It was designed by the concept that cartilage(iliac apophysis) has a specific inhibitory effect on bone formation and indomethacin inhibits bone resorption and bone formation in both heterotopic and orthotopic bone in rabbits. The following experimental groups were designed. Group 1 (N = 7) control group; no interposition material Group 2 (N = 7) iliac apophysis as an interposition material Group 3 (N = 7) only bone wax as an interposition material Group 4 (N = 7) bone wax with administration of indomethacin 10mg/kg/day The results of the study are as follows: 1. In control group, an osseous bridge were revealed as early as 2 to 3 weeks, and this bridging was found consistently in all control groups for the duration of the study. 2. The gmup using iliac apophysis as interposition material was found ineffective for prevention of the formation of epiphyseometaphyseal bone bridge. It was probably resulted from difficulty of its taking from iliac bone. 3. The group using administration of indomethacin after application of bone wax reduced both the angular deformity and growth retardation to a highly significant degree. From the results, it is recommended administration of indomethacin after insertion of silastic or bone cement as an interposition meterial in the elimination of transphyseal closure after physeal damage.