The research aims to develop student  worksheet based on a contextual approach to improve critical thinking skills in the economic subjects of the high school class, which uses to analyze and describe 1) the feasibility of resulting student activity sheets, 2) student responses to participants' activity sheets the students produced, and the effectiveness of using the student activity sheet on improving critical thinking skills. This study uses the 4D development models of Thiagarajan, Semmel, and Sammel (1947) which includes defining, design, develop, and disseminate. The types of data in this study are qualitative and quantitative data obtained from the study and validation of experts as well as filling in the questionnaire of educators and students. The trial design used in this pre-experimental study with the form of one grub pretest-posttest results were analyzed using n-gain. The results of this study are 1) based on the assessment of the material produced by student training sheets, a percentage of 98%, 91% of linguists, and 85% of graphic experts. From the assessment of the three experts, the average percentage was 89.6% so it could be categorized as "very feasible", 2) the response from students showed that it was very feasible because of the percentage of assessment reached 83.9%, 3) limited test activities are effective in improving students' critical thinking skills, this is evident in limited n-gain trials showing an average of 0.5 with a percentage of effectiveness of 95% and when the n-gain trial field shows an average of 0.7 with a percentage of effectiveness of 97%.