In order to take TOEFL Internet-based Test, vast majority of students spend several weeks and even several months preparing. In some countries like China and Korea, “Cram” courses are offered to provide students with the specific test practice. Techniques needed in the test are taught as core subjects in the syllabus. The fact that some learners who get a high score in TOEFL but cannot express themselves properly might due to this kind of negative washback which is named “learning for the test”. Additionally, TOEFL scores do not measure students’ actual language performance accurately. A negative impact happens when students define their own English proficiency according to the TOEFL strictly. It is quite possible for students to be successful communicating with native speakers of English orally and in written but not successful on the TOEFL iBT. Almost every formal test has these weaknesses in common, since its result means a lot to test takers.