Abstract: In recent years, imaging logging has become a research subject attracting wide attention. One of the key problem is how to identify the fractures in the imaging material of the wells. According that local fractures take the shape of plane, a fracture identifying algorithm was proposed. First, a line fitting most of the image pixels is determined. Second, the noise pixels far away from the line are deleted. Then the position of the line is calculated again. Repeat above process until the position of the line doesn’t change. This algorithm makes up the defection of traditional operation and has been used in a real problem, the results showed a good performance.