Pterocarpus marsupium (Roxb.) is an important medicinal plant in diabetes management. In the present study different stem bark samples (Apical bark, Middle bark and Mature inner bark) were analyzed with respect to phytoconstituents total reducing sugars, total sugars, amylose, amylopectin, starch, crude fibers, crude protein, total polyphenols, water soluble tannins, total flavonoids, total alkaloids, nitrates, total oxalate and total ash value. The concentration of constituents except oxalate and total ash was found higher in the apical stem bark than the middle and mature inner bark. The oxalate and total ash were higher in the mature inner bark than the apical stem bark and middle bark samples. Preliminary Phytochemical analysis indicated presence pharmacologically active phytoconstituents phenols, tannins, flavones, flavonoids, alkaloids, terpenoids, and cardiac glycosides. The saponins were found absent in all the three bark samples.