Abstract: The present invention relates to a novel 3-hydroxychromen-4-one derivative of formula (1), pharmaceutically acceptable salt, hydrate, solvate or isomer thereof which is useful as an inhibitor for Cyclin Dependent Kinase (“CDK”); to a process for preparing the compound of formula (1); and to a composition for suppression or treatment of cancer and diseases induced by cell proliferation such as inflammation, angiostenosis, angiogenesis, etc. comprising the compound of formula (1) as an active component together with pharmaceutically acceptable carriers.