Abstract: Based on a two-dimensional non-rank classification of two way indicative species analysis (TWlNSPAN), spruce and fir forest communities in Northwest Sichuan and South Gansu are divided into 15 associations belonging to 4 formations by using the DCA and TWlNSPAN classification methods.The dominant and indicator plant species are Smilax cyclophylla, Berberis dictyophylla (cold and moist, indicative of Moos-Abies forest and Rhododendron-Abies forest); Calamagrostis epigejos, Prunus lobulata (cold and dry, indicative of Calamagrostis Picea forest and Sinarundinar-Picea and Abies forest); Acer spp., Tsuga chinesis and Viburnum lobophyllum (warm and moist, indicative of Broad-leafed deciduous-Abies forest and Shrubland-Spruce forest); Helitotrichon boylei, Euvnymus przewlskii, Deyeuxia scacrescens and Chaemanerion angustifolium (warm and dry, indicative of Shrubland-Spruce forest and Spruce-Abies forest).