The North-west Pacific region is polluted seriously by marine litter, but has yet to establish legal system of cooperative governance. There are three typical institutionalized cooperative patterns, which are the North Sea and North-East Atlantic, the Baltic, and the Mediterranean patterns. By choosing two dimensions of the heterogeneity of the political system and the heterogeneity of economic development to analyze the three patterns' characters, generation mechanism, and the situation of North-west Pacific region, it can be found that the North-west Pacific region should choose the Mediterranean pattern, which are the fittest and the easiest to achieve. In order to absorb DPR Korea to join in, the North-west Pacific region, using the form of "Convention and Protocol", needs to formulate encouraging framework convention, which covers the contents of management structure and implement mechanism, etc. Based on that convention, the protocol to prevent marine litter pollution in the North-west Pacific region, which covers the concrete contents of the linkage to the domestic law, execution and supervision, and dispute settlement, should be formulated. And to make the intergovernmental organizations work at full capacity is also necessary. The cooperative governance pattern adopted for marine litter can pave the way for and lay the solid foundation for the integrated environmental cooperative governance legal system in the North-west Pacific region.