Basic structure of forest vegetation zones in east Asia can be characterized by four zones:tropical-subtropical rain forest(or monsoon forest) zone. warm-temperate evergreen broadleaf forest zone, cool-temperate deciduous forest zone and subarctic coniferous forest zone. Distribution altitudes of these zones change with latitude(thermal gradient) and longitude(humidity/aridity gradient) . In the present paper, the tendency of the change was studied and simulated from a view-point of eco-climatology, using a large number of geobatanical data. As results, the distribution altitude of the forest zones dropped from lower latitudes to higher latitudes in a humid climate region, and from the inland to the coast(from the west to the east) . Empirical equations of the three-dimension distribution for every forest zone were given based on the relationships mentioned-above, and their eco-climatological significance was described. The result of analyzing characteristics of these equations and applying these equations to actual data of vegetation distribution showed that these equations could described well the tendency of three-dimension distribution of the forest zones in east Asia. Accordingly, the equations provided a powerful method for predicting vegetation/climate zone, and had an important theoretical and applying value.