Abstract: To know the complicate character of bone material,which is anisotropic and non-homogeneous,three-point-bending tests were performed in wet and dry environments on mini bone samples which were cut in different directions,and load-flexibility curves were obtained.The bridging phenomena were recorded by optical microscopic digital video at the same time.And two types of fiber bridging in between the side wall of the crack were observed.One of which is directly made of Haversian lamellae in cortical bone,and the other type is of large number of fibrils of collagen,in different diameters of assembling scale.The method provided in this paper is very useful for analyzing the biomechanical characteristics of bone material in detail.