In this study, specimens were prepared by mixing expanded polystyrene (EPS) beads with mortar to simulate degradation, and sound specimens include no beads. Measurement of acoustic emission (AE) was performed using an AE transducer. The changes in AE behavior with increase in strain were measured for a uniaxial compression test and a splitting test. The behaviors were investigated in comparison to the change in the damage variable. The AE parameters (rise time, reverberation frequency and average signal level (ASL) ) were evaluated by the average every ten seconds.