This study aims to determine the effectiveness of the Project Based Learning (PjBL) learning model on student’s creative thinking skill on the topic of the human respiratory system. This research is an experimental research using Quasi Experimental Method with Nonequivalent Control Group Design. Data management uses SPSS 25. The results showed that the application of the Project based Learning model (PjBL) increased students' creative thinking skills with a gain of 47.4 and n-gain of 0.67 in the medium category. The results of the analysis of hypothesis testing show the value of Sig. 0.000 < 0.05 so that H1 is accepted. After the effect size test was carried out, a value of 1.15 was obtained in the large category besides that student responses have a good and process and product assessment has a very creative category. This indicates that the application of the Project based learning model has a significant effect on students' creative thinking skill on the topic of the human respiratory system.