The objective of this study was to investigate the ant proliferative activity of the successive solvent extract of leaves of plant of Barleria gibsoni Dalz. against MDA MB 4355 (Human breast cancer) and Hep G2 (Liver cancer cell line). 5 fluorouracil was given as reference drug. The leaves of plant were dried in shade and they were powdered and extracted with different solvents extract like petroleum ether, chloroform, acetone, ethyl acetate, ethanol. The preliminary phytochemical tests were done. Pet ether, chloroform extract of leaves showed that significant ant proliferative effects were obtained against MDA MB 4355 (Human breast cancer) by SRB assay method and ethanol extract of leaves showed moderate activity against Hep G2 (Liver cancer cell line) by MTT assay method due to presence of phytoconstituents present in the plant.