Abstract: AimTo study the inhibitory effect and mechanism of nobiletin on Heps tumor bearing mice. MethodsModels of Heps tumor bearing mice were established. The inhibitory rates of tumor growth were calculated, the apoptosis morphology of tumor tissue was observed. The T lymphocyte transformation capacity was tested by MTT assay, the TNFα and IL-2 production were measured by LDH kits. ResultsNobiletin could significantly inhibit Heps tumor growth. The inhibitory rates were 42.14%-65.09% (P<0.01). The morphology of tumor tissues in nobiletin group had typical characters of necrosis and apoptosis through transmission electron microscope. Nobiletin could stimulate T lymphocyte transformation and the production of TNFα and IL-2. ConclusionNobiletin has obvious antitumor effect on Heps, the main mechanism is to enhance the cellular immune function and induce apoptosis of tumor tissue.