To control the regional land development intensity from the environmental protection point of view, proposed method for determining the regional maximum trip generation rate based on environmental air capacity. A part of regional atmospheric capacity calculated by A value method was shared for environmental air capacity. Road network capacity was equivalent conversion to vehicle pollutant emissions. Then adjusted the network traffic volume to let vehicle pollutant emissions was equal to environmental air capacity. After removed transit traffic, used OD matrix estimation theory and adjusted network traffic volume to estimate traffic trips of each traffic zone. According to total traffic trips and available land area, regional maximum trip generation rate was calculated out. A certain region was selected as a numerical example and the result shows that proposed method is effective. Considering environmental air capacity in land development, it helped to protect traffic environment from root cause.