Abstract: In order to promote the application of the artificial freezing technology in the underground engineerings of city, a set of testing devices were developed to do frozen swollen experiment and thaw settlement experiment of artificial permafrost. According to three kinds of soil in Nanjing region, thaw settlement experiments were done at the selfdeveloped testing devices. The experiments results showed that the thaw settlement of soil occured only when the soil water content above the boundary water content. The thaw-settlement coefficient increased with the water content augment. Regarding to non-saturated soil,there existed a critical dry density between thaw-settlement coefficient and dry density changes. The critical dry density corresponded to the thaw-settlement coefficient in the smallest soil body. As there is the water source supply, thaw-settlement coefficient increases along with the temperature increment. When the water source doesnt supply, thaw-settlement coefficient reduces along with the temperature increment. Mealy sand is not the frozen swollen sensitive soil if it was compared with silt clay and mealy clay.