Abstract: The main biomes and ecotones along Northeast China Transect (NECT) were identified by means of the Model, Biodiversity Pattern Analysis (BPA) derived from the climate data sets measured since 1950s, and the Holdridge Life Zone System. Such a simulation was tested through the actual field investigation. The results show that locations and areas of the main biomes and the ecotones lying between them could be accurately distinguished through the BPA model. And the simulated distribution of biomes and ecotones was in agreement with that of actual geography location and plant community investigation. The responses of biomes and ecotones to global change can be also simulated using the Model. Under global climate change, the areas of some ecotones may increase. It is quite sensitive for the forest biome respond to the change of precipitation. There would be a large change in the location of grass biome, but the change in its relative area could be small. The shrub biome along NECT, nevertheless, would be most violent when global change occurs.