The spatial variation extent of the annual seasonal melt of Martian polar ice caps is the most direct reflection of Mars global and regional climate changes. A method that utilizes hyperspectral images from OMEGA spectrometer on board ESA Mars Express for monitoring Mars ice cap by extracting seasonal ice cap ablation line is proposed in this study. Based on OMEGA infrared images from 6 periods of Martian year 28 and 29 that cover Martian northern hemisphere, the boundary of seasonal ice cap was extracted by supervised classification method which can distinguish between ice and bare land, and the melting rate of seasonal ice cap was also calculated and analyzed, with validation from high resolution HiRISE images. The results show that the melting rate of Martian northern polar ice cap is about 10~6 km~2 every 10° solar longitude (LS). In addition, the comparison between the results and the terrain data from MOLA reveals that the regional abnormality of ice cap melting is mainly caused by the crater-induced topographic variation.