<p><em>This study aims to compare the effectiveness of Problem Based Learning (PBL) and Discovery Learning (DL) learning models </em><em>concerning </em><em>of problem</em><em>-</em><em>solving abilities of grade </em><em>students </em><em>of 4 Pandak Junior High School. </em><em>This type of research is quasi-experiment with The Nonequivalent Posttest-Only Control Group Design. The population of this research is students </em><em>grade </em><em> state of 4 Pandak Junior High School</em><em>. The samples for this research are students </em><em>grade </em><em>A and </em><em>students </em><em>grade </em><em>B</em><em>. The instruments of this research are observation, test, and documentation. Then data analysis techniques are a normality test using Kolmogorov Smirnov, homogenity test using Levene’s test, and hypothesis test use T-test with 0,05 as it significantly. </em><em>The final result of th</em><em>is</em><em> research </em><em>are (</em><em>1) Problem Based Learnin</em><em>g (PBL) models in terms of students mathematical problem-solving skills is effective are students </em><em>grade </em><em> </em><em>of 4 Pandak Junior High School</em><em>, it analyzed with one sample t-test method and it shown that </em> <em>); </em><em>(</em><em>2) Discovery Learning (DL) </em><em>models in terms of students mathematical problem-solving skill is effective are students </em><em>grade </em><em> </em><em>of 4 Pandak Junior High School</em><em>, it analyzed with one sample t-test method and it shown that </em><em> </em><em>; </em><em>(</em><em>3) There are differences between Discovery Learning (DL) learning models and Problem Based Learning (PBL) learning models</em><em> and</em><em> shown by the Discovery Learning (DL) learning model is more effective than Problem Based Learning (PBL) learning models in terms of problem solving abilities </em><em>are students </em><em>grade </em><em> </em><em>of 4 Pandak Junior High School</em><em>. It is proved with two samples t-test method, and the result is</em><em> </em> .</p>