Abstract: The purpose of this paper is to determine the relationships between students' learning styles and learning progress in a Web-Based PSI course to teach computer languages to college freshmen majoring in Mechanical Engineering. Results from Felder's Index of Learning Styles (ILS), used to identify students' characteristics and student progress over four semesters, were analyzed by a one-way ANOVA approach. Also, students' learning progresses were quantitatively captured by the differences between their progress curves and the average progress curve. Through the one-way ANOVA analysis we found that the students' scores on the "Active-Reflective" scale are strongly relevant to their learning progress. The Reflective learners showed better progress than others since they prefer to work alone. This gives us a reason to believe that Reflective learners are better able to perform on a Web-based PSI course than Active learners.