Heating confluence method in combination with response surface methodology (RSM) was performed to optimize polysaccharides extraction from Euphorbia caducifolia Haines. The Box-Behnken Design was used to optimize the extraction conditions with three parameters such as temperature (A), Solid to liquid ratio (B), and time (C). The percentage yields obtained were fitted to a 2 nd order polynomial equation using multiple regression analysis. From the regression equation, the optimal polysaccharides extraction parameters for 2.3% of yield are Temperature-120°C, Solid to liquid ratio-75 g/L, and Time-2 h. Further, crude polysaccharide was purified and disclosed GlaUA, Rha, Glc, Gal, Xyl and Ara (1:2.5:4:3.6:3.7:3.3) ratio of poysaccharide. Thermogram of the EC polysaccharide showed typical natural polysaccharide behavior, and hydrophilic nature of polysaccharide attributed to endothermic water loss. Furthermore, purified polysaccharides exhibited strong in vitro free radical scavenging activities, reducing ability, and immunomodulatory activity by the effective production of pro-inflammatory cytokines with RAW 264.7 cells.