Since Citibank in October 1995 took the lead in Internet banking, domestic public and private banks gradually build exclusive website. With the growing popularity of e-commerce, Internet banking will become an important competitive tool of individual banks. Internet banking in Taiwan grow very rapidly, showing the growing demand of internet users for Internet banking. Under a highly competitive environment, the operation of Internet banking is neither increasing the base of operations nor price war to raise market share. It needs to be stressed improving the service quality to strengthen customers’ confidence and satisfaction. So how to improve the service quality of Internet banking will become an important topic; therefore, the applicative aspects and criteria for service quality of internet banking has necessity to probe into. But on the assessment for service quality of Internet banking, there always has more or less interaction between aspects and criteria. This study adopts the fuzzy integral to calculate the performance of aspects and criteria on internet banking and analyzes key aspects and criteria with fuzzy measure. The study was integrated academia and the industry's views to come up with a suitable scale for measuring service quality of internet banking . Furthermore, in order to provide site design for Internet banking to improve and the basis of web service quality to upgrade, the study also analyzes key aspects and criteria of service quality of Internet banking. In empirical verification, this study reveals that customers pay more attention to the key aspects, which are security, reliability, system availability, efficiency and less attention to benefit. The key aspects and criteria of separated internet banking are different. In overall satisfaction with the service quality, Group E is not satisfied with the overall service quality of website. Group D is satisfied with the presences of the overall service quality of website provided by D. Further to use of kendall’ tau rank correlation to analyze the rank between weight and performance for both aspect and criterion that has correlated. It is found those internet banking did not complete consideration to aspects and criteria that customers value, therefore, in overall service quality and the satisfaction of each aspects still leave much room for improvement.