With the rapid growth of the Internet technology, e-Commerce has taken one major way of doing business. However, research on the measurement of e-Commerce service quality, has not been sufficient. Only the evaluation of web sites has been used to measure indirectly service quality of e-Commerce. Due to paucity of research on the measurement, the robust research result has not been achieved, and some research presented inconsistent results in the same domain. This research used WebQual, a measurement uniquely developed for e-Commerce service quality through continuous revisions, to measure e-Commerce quality of four representative Internet Bookstores in Korea. Some statistical analyses were conducted to verify the reliability and validity of WebQaul as an e-Commerce service measurement. According to the research results, WebQual was confirmed as a robust e-Commerce measurement in terms of its reliability and validity. Further, it is identified that e-Commerce service quality, customer satisfaction, and site revisit have positive relationships in sequence.