Density has a significant impact on performance of foam concrete. In this study, foam concrete with dry density grade of 300kg/m3 to 1000kg/m3 was prepared, and the slurry fluidity, compressive strength, water absorption and drying shrinkage were tested. Pore structures have also been analyzed by X-CT. Results showed that the fluidity of the slurry firstly increased and then decreased with the increase of the foam concrete density, and would reach to the maximum value at 600kg/m3. The compressive strength of the foam concrete increased gradually. The drying shrinkage and water absorption were all gradually reduced due to the decrease of internal porosity and the increase of closed pores. X-CT analysis showed that the pores in the foamed concrete with density less than 600kg/m3 were unevenly distributed, and there were more large pores on the surface of the specimen compared with the bulk. It is presumed that the volume ratio of the cement paste to the foam was too low to uniformly wrap the bubbles on the surface of the foam concrete.