Abstract: By using two Landsat remote sensing images (May 14, 1988 by TM sensor and May 10, 2001 by ETM⁺ sensor) and local meteorological data, this paper analyzed the causes and harms of urban heat island (UHI) in Zhengzhou City. The brightness temperatures of the images were calculated by mono-window algorithm, and related thematic maps were figured out. The results showed that with the expanding urban area of Zhengzhou City, the UHI effect was growing. Comparing with that in 1988, the high-temperature region of the City in 2001 had a clear shift and expansion towards northeast and southwest, being similar to the change trends of the low vegetation coverage area and urban land area. In order to alleviate the growing UHI effect, attentions should be paid on the urban greening work and the choice of reasonable greening patterns in the process of urbanization.

Key words: urban heat island (UHI), Zhengzhou City, land surface temperature, remote sensing, underling surface, loess hilly area, organic carbon, precipitation gradient, surface soil, land use.