The failure mechanism and damage form of unsaturated cement-based materials are rather different under freeze-thaw environment. In this paper, the water absorption characteristics of unsaturated cement paste at different freezing temperatures were investigated in four freeze-thaw cycle regimes, i.e. ?傆b10 ℃?傆b4 ℃, ?傆b20 ℃?傆b4 ℃, ?傆b30 ℃?傆b4 ℃ and ?傆b40 ℃?傆b4 ℃. The single surface immersed unsaturated cement paste was subjected to 23 freeze-thaw cycles at ?傆b40 ℃. The microstructures of the samples at different heights from the water surface were analyzed. The results show that the water absorption of unsaturated cement paste can increase with the increase of the number of freeze-thaw cycles. The lower the freezing temperature is, the greater the water absorption will be, indicating the greater cold absorption. After the same number of freeze-thaw cycles, the closer the site to the water surface is, the larger the porosity and the greater the volume fraction of microcracks will be. The smaller the content of small pores is, the larger the content of large pores will be, that is, the closer the site to the water surface is, the more serious the freeze-thaw damage will be.