Abstract: The formation mechanism of the widespread illegal curb parking behavior was studied, and a penalty amount calculation model was proposed for such behavior. Applying the game theory idea of tragedy of the commons, urban road curb resource consumption under optimal revenue of drivers' group and individual benefits was compared and the reason that the illegal curb parking on street without control was explained. In addition, the model of mixed strategy between drivers and traffic managers was established for illegal curb parking behavior, which provides the penalty amount standard for the illegal curb parking behavior under various management capabilities. Research shows that the disordered curb parking will appear just like tragedy of the commons if it isn't controlled effectively, and the game theory model of mixed strategy proposed is valuable in practice.