This study was performed to evaluate the physical and mechanical properties of porous concrete using waste activated carbon. Material used were ordinary portland cement, recycled coarse aggregate, waste activated carbon and superplasticizer. The replacement ratios of waste activated carbon were 0,1,2,3,4,5,6,7,8,9, and 10 %. The void ratio was decreased and ultrasonic pulse velocity was increased with increasing the waste activated carbon powder, respectively. The compressive strength and flexural strength of porous concrete using waste activated carbon powder were in the range of 8.21${sim1}$6.58 MPa and 1.69${sim1}$3.68 MPa, respectively. The pH degree of porous concrete in 1day and 77days were shown in 12.50${sim1}$12.63 and 10.21${sim1}$10.70, respectively. Accordingly, waste activated carbon can be used for porous concrete material.