The purpose of this study was to determine whether there are differences in guided inquiry learning model and conventional learning on the critical thinking skills of high school students. The sample in this research was done by random sampling as much as two classes, where the first class as experimental class applied guided inquiry learning model and second class as control class applied conventional learning. The instrument used in this study was the critical thinking skills test tool in the form of a description of four questions that have been declared valid and reliable. From the research result, it can be concluded that there is influence of guided inquiry learning model and conventional learning toward students' critical thinking ability, in this case the critical thinking ability of students were taught with guided inquiry learning model was better than conventional learning.

Keywords: guided inquiry and critical thinking skills