The objectives of this research is to improve the students' achievement through Problem Based Learning Model in accounting at the eleventh grade students of IPS 2 SMA Negeri 6 Surakarta.The research conducted by the researcher was Classroom Action Research. This research was conducted collaboratively among the researcher, classroom teacher, and involved the students' participant. The research subject is the eleventh grade students of IPS 2 SMA Negeri 6 Surakarta in the amount of 42 students. The technique of collecting data used were (a) observation, (b) questionnaire, (c) test, and (d) documentation. The procedure of the research were (a) planning of the action, (b) action, (c) observation and interpretation, and (d) analysis and reflection. Based on the research findings, it could be concluded that Problem Based Learning model could improve the students learning achievement in accounting. It was proven by the increased score of the students in cycle I. The research findings in cycle I improved or better than before research, 78,57% of the students had gained the minimum passing grade, that was 65. The mean score after the implementation of Problem Based Learning model got improved 4,18 (the score before the research was 69,05 and the score in cycle I was 73,23). In cycle II 40 students gained the minimum passing grade or 95,24%. The mean score in cycle II was 82,90. There was improvement in the mean score from cycle I to cycle II in the amount of 9,67 (cycle I score 73,23 and cycle II score 82,90). If it was compared with the situation before the implementation of Problem Based Learning model could improve students learning achievement in accounting. The implementation of Problem Based Learning model also could improve students interest, motivation and participation. It was proven by the increased students interest towards accounting lesson in the amount of 3,31% (students' interest in cycle I was 82,76% and in cycle II was 86,07%), the improvement of students' motivation was 10,36% (students' motivation in cycle I was 80,89% and in cycle II was 91,25%), the improvement of students' participation in learning process in the amount of 13,33% (students' participation in cycle I was 76,19% and in cycle II was 89,52%).