Collecting Landsat TM/ETM+ images of the whole region in 1990~2000, with the support of the object-oriented platform Ecognition, this research used decision tree and nearest neighbors classifier to extract the information about the land cover pattern of Northeast Asia, as well as its dynamic change. Based on the above datasets, choosing the involved area of China-Russia treaty, the coastwise transect area of Heilongjiang river basin, transect area of the frozen soils and Wusuli river basin of cross-boundary region between China and Russia as priority areas in this study, we discussed characteristics of land cover patterns and spatial differences of changes among different countries. Besides, taking related research about land suitable assessment as reference, we selected the most sensitive, most accurate and most abundant information indices as the assessment factor, according to the principle of comprehensiveness, leading character, rank character and regional rules. Then, we combined AHP (analytic hierarchy process) and expert evaluation method to illustrate the weight of different evaluation factors. After that, we did comprehensive suitable evaluation of reserved cultivated land in Northeast Asia. Finally, this study determined the spatial patterns and quantity of general suitable zone, highly suitable zone, fairly unsuitable zone and unsuitable zone. The result of this study can provide scientific support for sound land use policy makings.