In this study, different factors affecting students' differential equations (DEs) solving abilities were explored at pre university level. To explore main factors affecting students' differential equations problem solving ability, articles for a 19-year period, from 1996 to 2015, were critically reviewed and analyzed. It was revealed that combination of four factors; "epistemological math problem solving beliefs, belief about usefulness of mathematics, self-regulated learning (SRL) strategies and goal orientations" have great potential to enhance differential equation problem ability. Based on these findings, a conceptual model was developed and presented in this paper to enhance differential equation problem solving ability. This study has provided several important implications for the curriculum designers and teachers to enhance conceptual understanding in differential equation problem solving, particularly in the developing countries..