An analysis is made of the characteristics of the oceanographic and weather backgrounds in winter on North Pacific Ocean, based on the fundamental principles of ship weatherocean routing and the factors influencing the routing design. It is pointed out that the routing design should consider climatic condition, marine condition and weather patterns, as well as short/midrange weather forecasts. Through making full use of favorable weather and marine conditions, such as winds，sea waves and sea currents, ships can not only avoid adverse weather (strong winds, high waves, etc.) to ensure navigation safety, but also save navigation time and costs.