In this article, we analyze the decision of the Supreme Court in Korea with respect to the unauthorized modification of information and the immediacy of property disposal in a computer fraud critically. In the mentioned case, the defendant was charged with unlawful behavior to change the information by installing a hacking program on electronic bidding system of an administrative office. The author evaluated the defendant‘s conduct at issue not as an unauthorized change of information, but as an input of false information or illegal command input for computer. In terms of the immediacy of property disposal, this paper contends that we can’t say that computer fraud doesn’t hold, without exception, if a person involved in the property disposal process. In order to determine whether the computer fraud is established, we have to analyze the contents of the involved individual’s action in detail.