Urbanization has resulted in a continuous increase in the proportion of impervious surfaces within cities. Accurately determining the distribution of impervious surfaces is of great significance for the research on urban ecological environment. Based on Landsat 7－9 multispectral re-mote sensing images from 2003 to 2022, this paper employs a linear spectral mixture model to esti-mate impervious surface coverage in Changle District, Fuzhou City, and analyzes the distribution and variation patterns of impervious surfaces over nearly 20 years. The results show that high-albedo features in the study area are primarily distributed along roads, airports, squares, Binhai New Town, and commercial areas, while low-albedo features are mainly concentrated in the old urban areas dominated by aging buildings. From 2003 to 2022, the area of impervious surfaces gradually increased. In 2022, the area increased by 64.74 km² compared to 2003, with an average annual growth rate of 3.09%. Notably, the area increased most significantly between 2003 and 2013, with a total growth of 38.71 km², and the expansion was mainly located in the northern part of Changle old town and the Binhai New Town area in the eastern part of Changle District. This study provides methodological support and empirical evidence for the dynamic monitoring of impervious surfaces and the assessment of urban environmental changes in rapidly urbanizing areas.