Caesalpinia decapetala is important plant of Indian system used for antibacterial treatment. Roots, stem, leaves and fruits of this plant are medical importance. In the present work, leaves powered material was subjected for proximate, phytochemical and XRF analysis. Adsorption efficancy, toxicity of the plant to the mice and antimicrobial activity were also studied. The analysis must be carried out to standardized the medicinal drug obtained from C. decapetala. The phytochemical parameter such as water and ethanol soluble exact, loss on drying, foreign organic matter and total ash content governs the purity and quality of herbal drug. The phytochemical investigation reveals that leaves of C. decapetala contain water and ethanol soluble physiochemical and total ash in significant amount. Water and ethanol extractive values are essential for phytochemical investigation. Moisture content is also observed in significant amount. Phytochemical analysis was done by cold extraction processes. Extract obtained from cold extraction process was screened for qualitative and quantitative phytochemical analysis. The screening of aqueous extract obtained from C. decapetala leaves for preliminary phytochemical analysis shows that the plant is important source of phytochemicals like phenols, terpenoids, saponins, fats and fixed oils. These active phytochemicals were found in higher concentration. The nature of phytochemicals decides biological activity of plant. Thus it is important to study the biological potential of plant extract obtained from C. decapetala. (From Inside The e-Book)