Abstract: Aiming at the fact of seldom considering the restriction of road network capacity in parking planning,a parking berth scale optimization model based on the road network capacity restriction is set up.This model takes into account the restriction of road network capacity on parking demands,can lead parking demands to a reasonable distribution through the berth scale optimization of all parking plots to fully utilize road resources and maximize benefits and equities.The target of the model is to maximize benefits (i.e.,the total parking demands satisfied) under the constraint of road network capacity,and the user equilibrium traffic assignment model is used to calculate traffic flow assignment on road networks.The solution method of the model is introduced using genetic algorithms.A numerical example shows that the optimal berth scale of all parking plots can be obtained by solving the optimization model and the reasonable parking demand distribution can also be induced.