This study aims to determine differenes critical thinking ability of high school students in fungi using Problem Based Learning with concept mapping technique between the class that uses the application of the learning model and the class that uses the lecture method. This quantitative research applied quasi-experimental with nonequivalent control group design by involving first-grader Science High School students as the experimental group and the control group. The experimental group use Problem Based Learning methode with concept mapping but the control group use lacture and assigment methode in discussion. The one-sample Kolmogorov Smirnov test and homogeneity is used to select the experimental group and the control group. The experimental group using concept mapping to help problems in the course while the control group is not using concept mapping in the course. The evaluation of the data is using Independent Sample T-Test and the result shows the significant score is <0,05. Means that H0 is unaccepted and H1 accepted so Problem Based Learning method with concept mapping technique has an effect on students critical thinking.