Mars topographic mapping is the basis for scientific research of Mars. Firs街，Mars exploration tasks related to topographic mapping are introduced and the characteristics of mapping cameras are analyzed. Currently,the photogrammetric processing of stereo imagery is the main method to derive Mars topographic data, and the basic procedure of data processing and the conventional coordinate system of Mars are introduced as well. Then, the construction of rigorous geometric model of linear pushbroom imagery using SPICE kernels is discussed. The key techniques of photogrammetric processing for Mars topographic mapping such as bundle adjustment, dense image matching and montage of multi-linear CCD array are investigated. At last, some proposals are given to China on the Mars topographic mapping research.