The present invention is system and method of coding moving image in mobile communication terminal. The present invention includes one inside-flame coding process, in which the U and V components of target signal in compressed mobile image is coded via calculating average value in one 4*4 pixel unit, and the Y component of target signal in compressed mobile image is coded via discrete cosine conversion, quantization and Golomb-Rice in one 8*8 pixel block unit; and one inter-flame coding process, which includes estimating whether the motion appears in one 8*8 pixel block unit, classifying the block in mobile block or immobile block, storing mobile block or immobile block, coding and outputting the mobile block appearance information as grain mapping information and estimating the mobile block in inside-flame mode and inter-flame mode.