Transit-oriented development (TOD) is an urban planning approach that facilitates building resilient cities from urban planning and transportation perspective. Developed countries are moving in rapid, constant steps toward switching to a TOD urban fabric, yet developing countries still have challenges especially in the case of introducing new transportation modes such as the metro for the state of Qatar. To that end, the research study analyzes TOD from a system perspective, it analyzes in deep the interrelation between three modules; sustainable transportation, Built Environment, and economic subsystems as a whole TOD System. The authors in this research study defined the variables of the three modules, the causal Loops Diagram (CLD), then the Stocks and Flows Diagram (SFD) was developed, then the loops were investigated and analyzed in deeps. These assessments and modeling will crucially draw the lines for the policymaker for a better understanding of the interrelation between the mentioned TOD aspects to provide more effective policies. In this research study, a conceptual system dynamics model for Transit-oriented development considering the sustainable built environment, sustainable transportation, and sustainable economy is developed. Typically, Transit-oriented development studies investigate the development around the transit node, but this research study investigates the interaction between defined variables of the defined modules. The main finding of this research study is the causality effects between the selected variables, which leads to a conclusion that the TOD planning should work in a closed cycle of transportation, urban, and economic aspects. Moreover, the model developed in this research study was applied to the Qatar case but could have broader implications in countries that have similar conditions as Qatar.