成都市城市空间向东部台地丘陵区方向扩展不论从自然条件或经济发展规律等方面都是利大于弊。现代化城市是一个庞杂的多层次、多功能的动态系统，整个城市生态系统由许多不断变化着的子系统组成，而地市地貌子系统是城市生态系统的基础，因此城市的扩展方向，城市地貌着落的方向对城市生态系统总体功能的发挥至关重要。本文着讨了成都市向东扩展的有利条件，并提出了应克服的问题。

Chengdu, located in southest China, is an important city with ancient civilixation. The urban expansion direction is eager to delimit. Because the west, north and south of Chengdu all are plain, which exist an amount of fermaland. According to statistics, the farmland area reduces 2.713×10⁴ha during 1957-1987 and per capita farmland area reduced from 0.1ha (in 1949) to 0.5ha so that the agricultural development is limited. Therefore, based on the data of investigation and analysis, the expansion direction of Chengdu should be in the platform-hill area of east Chengdu. The favourable conditions are as follows:

1. It will be favourable to protect the fertile farmlands in the west, north and south of Chengdu, and to the agricultural developmen, so as to ensure urban supplies.

2. It will be suitable to vally-plain geomorphologic structure between plantflorm and hill and the stereoscopic vertical distribution of urban construction. This will form structure with a distinguishing.

3. Most of the basic materials of platform-hill area are of high strenth and bearing capacity. It will be suitable to construction of high and great buildings, as well as underground projects.

4. The major railways, highways and freeway in construction all run through the platform-hill area in east Chengdu. It has good transport facitites and will be favourable to the development of Chengdu.

5. The platform-hill area in east Chengdu is high, and will be easy to let waster and waste gas out so as to protect the urban environment.

6. The landform of east Chengdu is high. It may avert the flood and waterlogging disasters, problems in the expansion planning. The Zipingpu Reservoir in construction may be used to increase water supply for new city through the Dujiangyan canal. The basismaterials (clay disease) may be resoled through some engineering measures in construction.