Abstract: A multivariate analysis of woody plant communities with a 76 × 53 (sites x species) species matrix, 76 × 8 environment matrix and 76×2 spatial coordinates surveyed in the mid-section of northern slopes of Qilian mountain is presented. The results show: 1)nine communities (9 formations consisting of 17 associations) are identified from the 76 plots ( Kalidium foliatum shrubland, Reaumuria soongorica shrub, Nitraria tangutorum shrubland, Caryopteris mongolica shrubland, Caragana stenophylla shrubland, Caragana jubata shrubland, Potentilla fruticosa shrubland, Sabina przewalskii forest, and Picea crassifolia forest; 2) fifty-three woody plant species are classified into 5 ecotypes: hyper-desert, montane dry, montane intermediate, montane wet, and montane cold types; 3) the species abundance of woody plant communities explained by environmental and spatial variations reaches 23.98%;among these the species matrix explained by non-spatial environmental variation accounts for up to 17.66 % of variation, spatial variation that is not shared by environmental variation explains up to 1.40%, spatial structured environmental variation up to 4.92% and 76.02 % of undetermined variation remains due to biological and random factors.