Abstract: Polymetallic nodule's cover age data are used,which are calculated from the deep-tow system's optical image of the nodules,and based on the phase splitting of the poly metallic nodule's coverage in the east and west zones of China Pioneer Area in the East Pacific,the coverage's total length and average length which have continuous distribution of each phase,and the transitional changes between phase and phase are studied.The results show that the continuous distributing characteristics of the nodule's coverage between the east and west zones in China Pioneer Area of polymetallic nodules have obvious discrepancy.