This text carries on comparative research about Zhen He's trave to the West and the great geographical discovery, and probes into the differences in motive of science explorations, geographical knowledge, shipbuilding technology and navigation technology of the two and different influences produced from them. We believe that although Zhen He's navigation was far more advanced than that of the West on practical science aspects like scale, route, navigation technology, etc. it was inferior to the West greatly on science and culture aspects like motive of science explorations, scientific spirit, theoretical knowledge, etc. The difference of the science culture background is a deep reason which causes different final results of Chinese and Western navigation activities.