The science and practice of medicine and its primary source plays an important role in identifying the new molecule of drug through both synthetically and from that of natural origin. Most of the developing countries have adopted traditional medical practice as an integral part of their culture. Historically, all medicinal preparations were derived from plants, whether in the simple form of raw plant materials or in the refined form of crude extracts, mixtures, etc. The aim of this study was to evaluate the Cytotoxic Activity of Clerodendrum inerme (Family: Verbenaceae) and Caesalpinia crista (Family: Leguminosaceae), two widely distributed shrubs of the Sundarbans mangrove forest. A general cytotoxicity of all the extracts of C. inerme and C. crista were determined by Brine Shrimp Lethality Bioassay where the chloroformic extract of bark of C. inerme has the lowest LC50 value of 5