The impact echo method has been widely used to evaluate the integrity of concrete structures. This paper is to study damage detection technique of concrete members using impact echo method, one of the nondestructive tests based on stress waves. Stress wave propagation behavior is to be studied based on wave mechanics in concrete media. Based on the theoretical study, nondestructive tests using stress waves will be conducted to observe the wave behavior on structural damages. For the damage detection of concrete structures, a mock-up specimen was prepared, and various tests were conducted for the study of the behavior of stress waves. The concrete slab of the flaw detection consist of 5 types; the first group for the thickness presumption, the second group for the position of the voids, the third group for the position of the re-bars, the fourth group for the position conduit, and the fifth group for the position of the crack. Test results are evaluated and summarized to verify if the nondestructive tests can survey damages in the concrete structures in this paper.