Abstract:In this paper, the deviation sum of squares method of the clustering analysis is used to deal with the herbs beneath the frigid-temperate coniferous forest. The herbs are distributed on the shady slopes and semi-shady slopes of the mountains with an altitude of 1800–2800m above sea level in north Guan Qin-Shan area. The clustering analysis results are interpreted in combination with the environmental factors. The result indicates that the most important environmental factor which influences the distribution of herbs is altitude. Altitude has more-influence on herbs beneath trees than forest types. Thus the latter become the secondary factor of influence. The vertical zoning of herb distribution is as follows: 2850—2500m, 250D—220Dm and 2200—1800m. In the same altitude range, variation of the distribution of herbs beneath trees also exists owing to different behaviours of upper arbores, some physical and chemical characters of the soil and activities of human beings.