The principle of "utmost good faith" is one of the importantprinciples adopted in marine insurance. This paper, under the guid-ance of the theory of maritime law and with the provisions of Ma-rine Insurance Act of U. K- as reference, describes the insurer’sobligation in respect of the disclosure, including the materia1 cir-cumstances which should be informed, the time and standard of thedisclosure and the liability for no information.