The obvious problem in Animal Physiology class is that students are not capable in conducting analysis on the problems related to animal anatomical system. Laboratory practice has not yet proved its significance in developing students logical thinking process so as to solve problems. Students tend to memorize the materials, without mastering the physiological concepts, which entails low students achievement. The research method applied is Class Action Research posing research ojectives as to develop students cognitive achievement by implementation of problem-based learning. Research performance indicator is measured by the development of learning process quality and students achievement in problem-based learning. Throguh two cycles of research, the developments of learning outcome are: (1) 27.7% of lab practice, (3) 23% of lab practice report, (3) 22% of presentation of observation result and 24.7% of the written test.