ABSTRACT
This research aims to enhance the student’s activities and learning achievement of class X MIA 1 in SMA Bhinneka Karya 2 Boyolali in basic laws of chemistry subject matter with applying of problem solving learning method which equipped by worksheets. This research was classroom action research which consisting of two cycles. In each cycle has four phases of planning of the action, implementation of the action, observation and reflection. The subjects of the study were students of class X MIA 1 in SMA Bhinneka Karya 2 Boyolali in the academic year of 2014/2015. Data were obtained through interview, observation, test, and questionnaire. The data was analyzed using qualitative desciptive analysis. The result of this study showed that the application of problem solving learning method which by worksheets could enhance student’s activities and learning achievement in basic laws of chemistry material. Achievement for students activities rised from 70% at first cycle become 80,33% at second cycle. Then the student achievement consists of the competence of knowledge, attitudes, and skills. In the first cycle of learning achievement of knowledge competence 56,67% and increased to 76,67% in the second cycle. Learning achievement competence of attitude in the first cycle of 78,35% and increased to 81,9% in the second cycle. While learning achievement competence of skills in the first cycle of 70,83% and increased in the second cycle to 80%. Keywords: classroom action research, problem solving, learning activities, learning achievement, basic laws of chemistry.