This is a preliminary report of three cases of cranicplasties by implantations in situ with autologous bone matrix gelatin flaps. The excised cranial flaps obtained from cratliotomies were prepared by drillings and sa-w cuts

and then by chemical means for BMG.The follow-up perieds varied from 2 to 13 months. Rcentgenographi-cally.they showed active osteogencsis within 3 months after implantation and conti- nued for 8 months. Then it stopped extending.Clinical experiences proved the material is bio-active. It could induce osteogenesis. The brilliant prospect of cranioplas-ty encourages further detailed studies.