The aim of this research is studying the effect of web- based learning(weblog) by problem solving approach on English Literature student's reflective thinking, who study in Islamic Azad University of Ardebil. Required data for this study was gathered through reflective thinking questionnaire -designed by Camber et al on the basis of Maziro's Theory- in pretest and posttest form, for the two experimental and control groups each consisting of 15 students. Analyzing the gained data showed that there was significant difference between the two experimental and control groups regarding the level of thinking about the three categories of understanding, reflection, and critical reflection, and it was significant in T-test at level 0.05 and this shows that the weblog based learning affects on the development of student's reflective thinking.