This paper analyzes the severe situation faced by the City of Kunming in regards of urban land use patterns, urban roads, and the amount of cars traveling in the city, with traffic congestion worsened by a high pace of private car increase.

City population and the number of private car is growing fast.

As the rapid development of the economic in China, the urban population and the number of private cars have been expanding rapidly, which has occupied a great deal of social resources.

Since the demands on houses have been preliminarily met, it will play a crucial role in developing economics to initiate the consumption of private cars.

The results suggest that the city economic level plays an important role in the use of private cars.

Using "Gray System Theory",the predicting model of private cars in China is built and put to calculate.

Against the background of quick increase of the quantity of private cars in Chinese cities, this paper aims at studying the relation of person, car and road, which supplies necessary references to the transportation planning and construction of roads in urban communities.

According to different scale,structural layout and land use characteristics of cities,to give priority to the development of public traffic energetically,advisably develop private cars in reason,establish a urban traffic system that can reduce traffic congestion,deduce traffic pollution,save energy,be propitious to urban environment and be composed of diversified urban transportation tools.