International loan is a very important business for Taiwan commercial banks, and China is the largest credit market for Taiwan banks. However, when doing due diligence or credit risk research for Chinese companies, Taiwan commercial banks are facing difficulties and risks such as difficulty to monitor the company, a decelerating Chinese economy growth and other risk factors. Because of these difficulties, the common method used for international loan due diligence in Taiwan is not adequate to cope with the current credit risk situation. There were two famous Chinese default cases in Taiwan during 2014, in which the thesis picks the Ultrasonic AG financial fraud case as an example. The Ultrasonic AG case shows that it is possible to use public information to detect and prevent financial frauds. Based on the case study, the thesis suggests Taiwan commercial banks could use a more comprehensive method of due diligence, to increase the accuracy of credit research. In the end, the thesis also suggests a KL credit scoring system, based on past financial frauds, to assist in credit research. By utilizing a more comprehensive method of due diligence and KL score system with traditional models, Taiwan commercial banks could better detect and prevent international financial frauds, especially financial frauds in China.