he Graduate School of Chulalongkorn University has realized the importance of English because it can help students to acquire knowledge from all over the world. Therefore, it is a requirement that all students who apply for the Graduate School at Chulalongkorn University have to take the Chulalongkorn University Test of English Proficiency (CU-TEP) before being admitted. One of the missions of the Academic Testing Center of Chulalongkorn University (CU-ATC) is to administer the CU-TEP to all applicants. The test has been developed to be a general proficiency test of English to measure listening, reading, and writing skills. Not only do we want to measure the students’ abilities, but we also would like to know how well our tests can discriminate the examinees. This has led us to conduct a research survey.