The paper usedl Hefei city as the research ara and 6-temporal Landsat satellite images as the data source,andthe visual interpretation method and support vector machine( SVM) method were adopted for supervised classification andaccuracy evaluation of remote sensed Hefei images.The paper analyzed the temporal and spatial changes of Hefei's built-up areas with indicators such as compactness index , fractal dimension , and index of shifting center.The research resultsshowed that :( 1) From 1995 to 2013 , the expansion of Hefei's built-up area mainly diverged from the center to the mar-ginal areas of the city.From 2013 to 2018,the expansion of the built-up area was mainly an expansion within the region ,that was , " inmfilling expansion" .From 2018 to 2020 ,the expansion of built-up areas was mainly an " enclave-style expan-sion".( 2)The center of the built-up area shifted to the west and southwest areas ( including the northward shift in 2013-2020).(3 ) The built-up area of Hefei city had been expanding with a napid speed from 129.64 km2in 1995 to 884.03L...2 :. o0on