This research is motivated by PISA result which shows that students' critical thinking ability in Indonesia is still low. This is in line with the results of observations in the field of researchers who showed that students in Indonesia, especially in District Katapang on average not ready in solving problems that require high-order thinking skills. Therefore, an effort is needed to improve the ability to think critically, one of them is by using ARIAS based learning model of scientific approach. The ARIAS-based learning model of a scientific approach is a collaboration between the ARIAS learning model and the scientific approach that requires students to play an active role and to think in a high level of learning. This study aims to determine: 1) differences in critical thinking skills before and after applied ARIAS learning model based on scientific approaches; 2) differences in students' critical thinking skills before and after using conventional learning models; 3) differences in students' critical thinking skills between those treated using the ARIAS-based learning model based on the scientific approach and the conventional learning model. The research method used is quasi experiment with design type nonequivalent control Group Design which use two groups that is experiment group and control group. The population in this study were all students of grade V SD Negeri Sukamukti 02, while the sample in the study were VA class students and VB Elementary School students Sukamukti 02 District Katapang District Bandunng District. The data analysis technique used is the data analysis using the software SPSS version 17.0 for windows. Based on the results of data analysis can be concluded that there is a significant difference between the application of ARIAS learning model based on scientific approach with conventional learning model, it is proved by the test result of pre-test post-test experiment class showed significance level of 0.040 with the difference of 12 , 50 while the pre-test result of post-test of the control class showed a significance level of 0.039 with an average difference of 6.83. Thus it can be concluded that ARIAS learning model based on scientific approach can be used by teachers as an alternative to improve students' critical thinking ability.