Abstract: The curing conditions of concrete have significant influences on both the hardening of concrete and the formation of its micro-pore structure, and the capillary absorption is closely related to the structures and distributions of the pores within the material so that the curing conditions can influence the water absorption process of concrete. The objective of this paper is to carry out experimental studies of the influences of four curing conditions (i.e. standard curing, natural curing, water curing and sealed curing) on the capillary absorption of a normal strength concrete. The compressive strength of the cylinder specimens core-drilled from concrete slabs is tested. The measurement of ultrasonic pulse velocity (UPV) and porosity is then implemented with “pie” specimens cut along three different elevations of the cylinder specimens. A series of water absorption experiments are conducted on the “pie” specimens by an improved gravimetrical test apparatus to measure the cumulative water absorption variation, realizing the continuity of water absorption testing. The test results indicate that the curing conditions of the concrete have a great influence on its compressive strength, UPV and porosity, which is the key factor to determine its strength development, internal pore structures and compactness during the curing process. The compressive strength and UPV of the specimens are the largest and the porosity is the smallest under the standard curing conditions, whereas the compressive strength and UPV of the specimens are the smallest and the porosity is the largest under the sealed conditions, the case is exactly the opposite, and the results in the natural curing and water curing conditions are close to each other, lying between the standard and sealed curing conditions. For the same curing conditions, the cumulative water content, absorptivity and porosity of concrete gradually decrease with the increase of the surface distance, but the UPV gradually increases, which implies the gradual increase of the concrete compactness from top to bottom.