Learning received by biology teacher candidates students should encourage them to think critically and become problem solver. The learning model that theoretically could stimulate critical thinking is the OIDDE (Orientation, Identify, Discussion, Decision, dan Engage in behavior). This study aim to describe the application of OIDDE learning model and to analyze the improvement of ten indicators of critical thinking skills. This research was a Classroom Action Research that conducted with Lesson Study. The research subject is 47 students, semester V, who take Environmental Science course in Biology Education Department, University of Muhammadiyah Malang. The study was conducted in 2 cycles, each cycle consisting of two meetings for 3x50 minutes. Each meeting is carried out with Lesson Study stages of Plan, Do, and See and combined with classroom action research. The data were analyzed descriptively qualitative supported with quantitative data. The results show that 1) OIDDE learning model has been implemented in according to syntax, the process improved in each cycle, and 2) ten indicators of critical thinking skills have increased, i.e. objective 16.9%, problem 17.8%, address the problem 22.3%, viewpoint 24.3%, information 19.5%, concept 21.2%, assumption 12.5%, alternative solution 8.1%, interpretation 21.0%, and implications 21.8%. All indicators in cycle 2 based on the average are excellent category.