The study aims to find out first, whether there is a difference between the learning model of Assurance, Relevance, Interest, Assessment, and Satisfaction (ARIAS) and Problem Based Learning (PBL) on the concept mastery of temperature and heat. Second, it also aims to investigate the effectiveness of ARIAS and PBL learning model on the concept mastery of temperature and heat. The study uses Quasi-Experiment method with Nonequivalent Control Group Design, and sample selection with Cluster Random Sampling technique. This technique consists of two classes, i.e., experimental class I applying ARIAS learning model and experimental class II applying PBL model. The technique of data collection uses test instruments (pretest and posttest). The result of t test with 5% significant level indicates that t calculate = 2.03 > t table = 1.99, thus, it is concluded that (1) there is a difference using the learning model of ARIAS and PBL on concept mastery. The result of Effect Size test is a score of 0.45 with the medium category. Based on the result, it can be concluded that (2) using the learning model of ARIAS is more effective than PBL on the concept mastery of temperature and heat in high school students.