In order to ordination of weeds and rangeland plants, investigations were done in Khalatposhan rangeland of Tabriz county in 2013. Vegetation in each section was sampled by 176 plots (0.5 m × 0. 5 m) in grid method (20 m × 40 m). Data of presence and absence plants in different sections were analyzed through two-way indicator species analysis (TWINSPAN) and cluster analysis (CA). One hundred species (83 Dicotyledonous and 17 monocotyledonous) belonging to 75 genera and 20 families were recorded along 176 stands in Khalatposhan rangeland. Asteraceae had the highest contribution (23% of the recorded species), followed by Poaceae (13%) and Papilionaceae (12%). TWINSPAN analysis showed that sections 5 and 7 had similar species such as Artemisia sp., Atrriplex tatarica, Capsella bursa-pastoris, Xeranthemum squarrosum and some others. Lepidium vesicarium and Verbascum nudicaule were observed in sections 5, 6, and 7. CA showed that in 50% similarity, four sections were separate, also sections 5 and 7 were located in the same group, and confirmed TWINSPAN results. In high level of this classified, separation is precisely and analysis of sampling units will be correctly. In 100% similarity, sections 3 and 4 were located in one group and had maximum similarity (43 species observed in these two sections).
