中文摘要：

选取1951—2004年中国东部地区9个大城市和较近距离的9个小城市，对城市逐月平均最高、最低和平均气温资料进行不同季节的城市热岛效应分析，对描述热岛效应的热岛强度指标进行研究，并提出一种基于气温日较差的新的热岛强度指标。结果表明，1980年以后，无论大、小城市，城市化的热岛影响均有所加强。大城市年热岛强度10a约增加0．20～0．34℃，小城市约增加0．14～0．20℃。大城市的热岛强度无论季节或年增加幅度均比小城市大，特别是冬、秋季，而小城市则主要表现在夏、秋季。

英文摘要：

Several existing urban heat island （UHI） intensity indices are examlned in mls paper oy using the monthly average maximum, minimum, mean temperatures data in nine big cities and their nine nea- rest small cities in eastern China;then a new HUI intensity index based on temperature diurnal range （TDR） is proposed. The research results show that the effect of HUI since 1980 both in the nine big cites and nine small contrast cities has enhanced; the intensity of HUI increased about 0. 20 - 0.34 ℃ per ten years in the big cities, and about 0. 14- 0.20 ℃ per ten years in the small cities ; its increase amplitude whether on seasonal or annual time scale was larger in the big cities than in the small cities, especially in winter and autumn, while the increase amplitude in the small cities was larger in summer and autumn than in winter and spring.