Korean civil code Art. 390 prescribes that the debtor has responsibility to compensate for the non-performance only if he is to blame for non-performance. The criteria of debtor’s fault has been focused on his negligence on the act of performance. A couple of cases in this article that show the meaning of fault in contract law, deal with the issue of information in context of contracting and performing. For example the debtor did not provide appropriate information about risk immanent in performance or rejected to perform on ground of false legal judgement. These reveal that the issue of information provides the most important basis to judge the risk allocation of both parties in contract relation. To acknowledge the fault of debtor means that the realized risk of non-performance is allocated to debtor. The decision of fault is the first step of risk allocation. To evade the dispute of posterior risk allocation it is recommended to deal with the risk at the stage of contracting. The information about risk immanent in contract should be revealed at proper time, so that it may be assumed or not. On the other hand to collect and judge the information related to performance accompanies in principle taking the risk of decision.