The built-up area of Zhengzhou has been changed greatly during the past 28 years. Based on remote sensing and GIS technology, the authors used a time series of Landsat MSS and TM images to extract the change of the built-up area in Zhengzhou. The results show that the built-up area increased by 5.81 times from 1976 to 2004 and expanded by about 10.75 km2 each year. Large amounts of arable land, rural land and industrial and transportation land were converted into the urban built-up area, and some forest land, reservoir and wetland were also turn into the built-up area. The natural environment is the limiting factor for the urban expansion; the economic development and, especially, the increase of GDP and the growth of average salary make up the fundamenta1 driving forces; the policy and the urban planning are the guidance of extension of the urban built-up land. The influence of urban expansion from 1976 to 2004 on the peripheral land in different dynamic periods can be easily obtained from the monitoring result, which can help people understand the rule and characteristics of urban expansion and properly deal with the contradiction between land use and urban expansion.