1. The southeastern part of Xizang is abundant in its specific topography, ecotype, biotic population and forest vegetation. In this region, there exist a large number of ancient, healthy and natural forest ecosystems, among which the subalpine dark coniferous forests are found to be a widly distributed, extensively stretched, stable and high productive formation group.2. The subalpine dark coniferous forests in Xizang are among the cold-temperature dark coniferous forests, which are lotatcd in the southern-most part and at the highest altitude. Due to the habitat diversity of the three main slopes of this mountainous region, horizontal districts and vertical zones are distinctly presented. They are different from each other in dominant trees, forest types and growth con? ditions.3. Horizontally, the area covered by subalpine dark coniferous forests in Xizang can be divided into three districts, namely:(1) Dispersed subalpine dark coniferous forestplots in the gorges in the Three Rivers area.(2) The moist subalpine dark coniferous forests in the valleys at the southern foot of Mt. Himalaya.(3) The subalpine dark coniferous forests in the canyon along the middle and lower reaches of the Yalu-Tsangpo River.Picea, Abies and Sabina formations occur at the elevation from 2700 to 4000m, each composed of different forest types based on different thermol and water conditions.4. The characteristics in the growth of the subalpine dark coniferous forests in Xizang are their tallness, longevity and high production. In the humid area at the southern foot of Mt. Himalaya, a Picea stand holds the maximum volume of 3500 m3 per hectare, with a mean diameter of llicm. and an average height of 67m. In the same stand the maximum diameter of an individual tree is 162cm and the maximum height is 72m.5. The growth of the subalpine dark coniferous forests vary distinctly at different elevations as well as in different slop 2 directions. At the humid southern foot of Mt. Himalaya, 2700-2800 m is the optimum growth altitude for Picea and 3600-3700 m. for Abies. Forest stands on the southern slopes grow much better than those on the northern slopes.