This research is a research and development (R&D) using ADDIE (Ananlysis, design, development, implementation and evaluate) method, aimed at developing Macromedia Flash learning media and knowing the improvement of students' chemistry learning outcomes. The sample consisted of 3 chemistry validator lecturers, macromedia flash, class XI Science -1 (27 students) for the experimental class and XI Science -2 (27 students) for the control class from High School Muhammadiyah 1 Medan. Learning in the experimental class problem-based learning model (PBL) with Macromedia Flash is the result of development, and in the PBL control class without Macromedia Flash. Macromedia Flash validation developed using the BSNP instrument, obtained an average content worth of 4.39; language 4.66; presentation 4.39; and graphic 4.33; on average all aspects are 4.44 (very feasible category). Learning outcomes data were processed descriptively and analyzed with one-party t-test, obtained an increase in student chemistry learning outcomes with the experimental class gain 80.00%, and the control class 72.00%. Hypothesis testing obtained tcount> ttable is 4.396 > 1.672. Conclusions that the application of macromedia flash learning media as a result of development in PBL can significantly improve student learning outcomes in equilibrium material in class XI Science High School.