Abstract: A curve description and matching algorithm which utilizes the scale constant is presented for feature tracking and hazard recognition process in planetary landing. The way to form the curve descriptor which is constructed with the curve neighborhood gradients information is introduced. The robustness and the efficiency of our graph matching process is shown in rotation , scale , moderate viewpoint changes and light effects , without knowing the curve geometry or geometrical configuration between the curves. This algorithm can not only be used for edge curve feature tracking with low mismatching,but also effectively identify the craters , rocks and other hazardous or natural landmarks at different scales.