Present study in Hastinapur wildlife sanctuary in Indian dry tropics aimed to understand vegetation structure and soil characteristics in areas invaded by invasive tree Prosopis juliflora (PJ site) and invasive weed Parthenium hysterophorus (PH site). Plant density was estimated through 120 random quadrats (each 1m x 1m) across the two sites in three seasons. Diversity and similarity of the two sites in different seasons was estimated. Nine soil samples (0-10 cm) from each site in different seasons were analyzed for their pH, moisture content, total N, organic C, exchangeable Na, K and Ca. A total of 74 plant species distributed across 30 families were recorded. Largest families were Amaranthaceae, Fabaceae, Malvaceae, Poaceae, Asteraceae, Solanaceae, Lamiaceae, Euphorbiaceae, and Acanthaceae, together accounting for over 65% of total flora. Largest number of flora in both sites occurred in rainy season (60), followed by winter (52) and summer (50). Diversity indices ranked sites differently. Species richness and evenness showed greater diversity at PJ compared to PH site in all three seasons. Beta diversity range indicated least variation in rainy and it increased in summer and winter. Species common across sites and seasons included Cynodon dactylon and many alien weeds Cannabis sativa, Parthenium hysterophorus, Lantana camara, and Ageratum conyzoides. Dominants and their associates changed with season and site and this dominance increased in non-rainy months, as evinced by dominance-diversity curves. Higher inter-site similarity was noted during the rainy season followed by the winter and summer. Dissimilarity of vegetation patches was more prominent in summer and winter. No general trend in soil characteristics could be deciphered. In conclusion, the study revealed a complex interplay of seasonal dynamics and invasive species interactions on plant community structure and soils in Indian dry tropical ecosystems.