In this study, collagen was implanted into mandibular defects of 10 dogs. After operations, the samples were examined with microscope and quantitative method at 10 periods. Results showed that collagen did not affect bone growth and new bone grew into collagen directly. There was no fibrous capsule between collagen and new bone. Eventually, majority of collagen was resorbed and replaced by bone tissue. It was concluded that collagen has a good histocompatibility.