Purpose: The purpose of this study was to compare the effect of KWL educational strategy and conceptual mapping strategy on students' critical thinking. Methodology: This research was based on a quasi-experimental design with pre-test and post-test with two experimental groups and one control group. The statistical population consisted of all male students of the third grade high school of Miandoab in 2016-17. Three classes were selected through multistage cluster sampling. Two classes were randomly selected as experimental group and one class as control group. One of the experimental groups was taught in KWL and the other in a conceptual map. The control group was also trained in a conventional way. The pre-test and post-test data were used to collect data from the California Formation B Questionnaire. Findings: To analyze the data was used one-variable covariance analysis. The findings of the study showed that education through the Kwl strategy and conceptual mapping strategy is effective on critical thinking students (P <0.001). It was also determined that the effectiveness of KWL strategy on students' critical thinking was more than conceptual mapping strategy (p <0.001). Conclusion: Based on this study, both cognitive strategies and metacognitive strategies reinforce students' thinking. However, due to the findings of this research and related studies, it is better to use metacognitive strategies along with cognitive strategies because using metacognitive strategies, students monitor their learning process and become more aware of complex issues and points and they get more aware. Based on these findings and previous research, it is recommended that modern educational methods such as KWL and concept maps be used in teaching
