Anti-metastasis have received increased research effort and clinical attention. The anoikis-sensitizing effect of ecteinascidin 770 (ET-770) was investigated in the present study in non-small cell lung cancer cells. ET-770 isolated from Ecteinascidia thurstoni was tested for its anoikis-sensitizing effect on H23 human lung cancer cell by XTT assay. The levels of proteins involving in anoikis of cells were determined by western blot analysis. ET-770 was shown to enhance anoikis response of human lung cancer H23 cell in a dose-dependent manner. The underlying mechanism was investigated and it was found that ET-770 sensitized the cells by activating p53 protein, which in turn down-regulated anti-apoptotic MCL1 and up-regulated BAX proteins. However, BCL2 and CAV1 proteins were not significantly affected by ET-770. Furthermore, the anoikis sensitization of ET-770 was observed in H460 lung cancer cell. The results reveal for the first time that ET-770 can sensitize anoikis through the p53 pathway and further development of this compound for therapeutic use is warranted.