The International English Language Testing System (IELTS) and Warwick English Language Test (WELT) are both criterionreferenced tests which are designed to assess whether a candidate has sufficient linguistic proficiency to study in the medium of English at an undergraduate or postgraduate level. This paper analyzes and compares the reliability and validity of the sections of reading comprehension tests of the two from such perspectives as authenticity, question number and types and so on based on expression forms, difficult coefficients, theme selection and reading comprehension task of the texts.