Abstract: Lung cancer has high incidence and mortality rates around the world and chemotherapy is widely applied in cancer treatment. Doxorubicin (DOX) is a kind of chemotherapy drug which commonly used in clinical trials. However, the drug has many side effects and may cause a dose-dependent injury in the long term. These side effects include irreversible cardiopulmonary, bone marrow suppression and so on. Moreover, its mufti-drug resistance also restricts it in certain clinical application. The effect of polysaccharides of tea extract combined with doxorubicin on human lung cancer cell line A549 were tested in this study. A549 was first cultured in vitro with different concentrations of DOX. After 24h culture, apotheosis ratio was determined by MTT. The results show that the DOX dose for the best inhibiting effect was 3 mg·L^-1 according to MTT detection. Three doses of DOX were selected to combine tea polysaccharide and suppress A549 cell survival. The combination of 2 mg·L^-1 DOX and 6 mg·L^-1 tea polysaccharide had been demonstrated to have better suppressing efficiency than 3 mg·L^-1 DOX alone. DOX could

Key words: tea polysaccharides, doxorubicin, antitumor