ERUKKU (Calotropis gigantea)Erukku (Calotropis gigantea (L.) R. Br. Ex Ait. ). (Fam: Asclepiadaceae) is an important medicinal plant used in the Siddha System of Medicine. The medicinal use of the flower is reported as bile suppression, elimination of intestinal worms, coughs, colds and asthma. The leaf of the plant is used to treat skin ulcers, leprosy, etc. The latex of the plant is used as a violent purgative, gastrointestinal irritant and abortion inducer. It has also been used in the treatment of toothache, earache, headache, sprain and stiff joints.The chloroform extracts of leaf, flower and latex of C. gigantea were subjected to HPTLC and Ultra Violet-Visible spectroscopic analysis. The physico-chemical parameters, HPTLC finger prints and the spectra obtained can be considered as unique for the chloroform extract of leaf, flower and latex of C. gigantea.