A new chromanone derivative, namely caloinophyllin B (1), along with seventeen known compounds 2–18 were isolated from the root bark of Calophyllum inophyllum. The structures of all isolated compounds (1–18) were determined by spectroscopic methods as well as comparison with previous reports in the literature. To the best of our knowledge, compounds 1, 3, 6, 8, 11–14 and 16 were isolated from this plant for the first time. Moreover, all isolated compounds (1–18) were evaluated for their cytotoxicity against KB and Hela S-3 cell lines. Compound 8 exhibited moderate activity toward KB and Hela S-3cells with the IC50 values of 25.8 and 18.1μM, respectively.