A Contract of marine insurance is a contract whereby the insurer undertakes to indemnity the assurd, in manner and to the extent thereby agreed, against marine losses that is to say, the losses incident to marine adventure. But the matter is that whether the problem of increased risk in insurance law should be understood by matching to nay state under general principle of contract law and whether that we should give any effect is more proper to the original object of the system. For this, it is understood that it is a case to be applied a "clausula rebus sic stantibus" in general today, but it is regarded as the matter that whether "clausula rebus sic stantibs" is charging any position in change of risk and whether we should understood the concept of the risk on the substance of the risk. Accordingly the recognition for the problem like this, study should examine closely into whether any system for the effect of increase in change of risk is more proper and rational system provide the supplementing points through our principle of insurance law and the study by comparing method.by comparing method.