As a subject of studying all of the past and existent patterns of biological distribution of geography, biogeography tries to describe the innumerable distributive patterns of the species and the superior classed taxon, and deduce their processes. Taiwan Island is off the coast on the southeast edge of continental shelf. As a part of Fujian-Zhejiang promontory, which were from the Yanshan Movement in the middle and late Mesozoic, Taiwan is a land bridge island, which was divorced from the continent in late ice age. We deem that the historic biogeography interpretation on distributive patterns of geography for both sides of the Taiwan Strait ought to be as a result of the adaptation for diverse environments, which appeared after a large biota existed to the south of Yangtze River had been segmented during the last ice age period. Therefore, targets of the biogeography study for cross-strait should focus on the following five aspects: the influence on distributive patterns which owing to the vicissitude of the ocean and the mainland since the last ice age, the phyletic relationship of biota between two sides of the Taiwan Strait, the period and the range that Taiwan kept final connection with mainland, the influence from the other arched-arranged islands in East Asian on patterns of biological distribution in Taiwan Island, and die species differentiation and the ecological adaptability for the organisms sharing by both banks of the Taiwan Strait.