The Thandiani sub forests division in the lower western Himalayas lies at an important geographic location. Variations in its aspect and elevation further enhance its high floristic importance. This study was designed to follow the objectives i.e., measurement of phytosociological attributes, Estimating vegetation dynamics, identification of the environmental variables responsible for the vegetation variation and identification of indicator species for future conservation and management. The species attributes were measured along latitudinal gradients using quadrat and transect methods on slopes with different aspects (elevation range 1290-2626 m). Two hundred and fifty two plant species from 79 families were quantified along 08 elevation transects with 50 station and five different plants associations. The elevation of the study area was determined via GPS. Personal Geo-database (pertaining 3D analysis of surface data) was created in ArcGIS 10.2.1 to save all Geo-datasets. It was hypothesized that aspect, altitude and soil composition were the main driving forces of vegetation composition. The low p value (p ≤ 0.002) showed that the variation in the vegetation composition in the study area was highly significant in terms of test statistics. Classification and ordination techniques (PCORD & CANOCO) identified 5 major plant communities. Indicator Species Analysis (ISA) and an assortment of fidelity classes identified indicator/characteristic species. Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) showed altitude and aspect to be the strongest drivers of community classification. The vegetation changed from a subtropical to moist-cool temperate community characterized by woody species. Plant species diversity reached an optimum at mid-altitude (1700masl to 2200masl) as compared to lower (1200masl to 1700masl) and higher elevations (2200masl to 2600masl). Variations in species richness and composition among sites ultimately led to varied vegetation types. The family Pinaceae was the most abundant family with 1892.4 Family Importance Value (F.I.V), followed by Rosaceae with 14.78.2 and Ranunculaceae with 762.1 Value respectively. Out of 79 plant families the most abundant plant family in term of species, was Asteraceae with 20 species and followed by Rosaceae and Lamiaceae with 19 and 13 plant species each. It is concluded that altitude, aspects, soil composition were the main factors affecting vegetation composition of Thandiani sub forests division. This study contributes to an enhanced understanding of (i) plant diversity in the Western Himalayas; (ii) ecosystem service values of mountain vegetation within the context of anthropogenic impacts; (iii) local and regional plant conservation strategies and priorities.