Flavonoids, a class of normal polyphenolic mixes, restrain cell cycle movement and instigate apoptosis. This examination was performed to explore the anticancer effect of theaflavin, a natural flavonoid found in the leaves of tea plant Camellia sinensis. Although this molecule was found to inhibit several cancer cells, the specific anticancer action in liver cancer remains unexplored, especially in human hepatocellular carcinoma (HepG2) cells. Henceforth, the present study was designed to elucidate the anticancer activity in HepG2 cells, level of reactive oxygen species (ROS) in the cancer cells and tumour cell apoptosis. The action of theaflavin in provocation apoptosis was explored through the improved ROS by MTT assay and 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) method. As per the results obtained from the MTT assay, theaflavin had cell hindrance effect on HepG2 cells. The IC50 estimation of theaflavin to hindered cell development at 25, 50 and 75 μM concentration and instigating apoptosis through ROS improvement. The progressions in mitochondrial morphology, portion conditionally that diminished cell expansion, were seen in various concentrations of the drug treatment. In this manner, theaflavin might be useful as a chemotherapeutic agent for the treatment of liver cancer.