Abstract: To understand the characteristic of Kaiser effect along different stress paths during cyclic load acting on rock, a numerical computation was conducted using the rock failure process analysis software RFPA^2D for the characteristics of acoustic emission (AE) along three different stress paths in rock specimens. The results showed that the Kaiser effect is still clearly observed in the subsequent cycle when the specimens are under cyclic load though a big difference between KF values (the stress value at Kaiser effect point) and previous max stress value is found. It was revealed that what was actually recorded in the Kaiser effect memory is the damage level within rock other than the max stress acting previously on the specimens. So, if sampling from parent rock, the stress value measured from observing KF value by uniaxial compression AE testing in laboratory is different greatly from that in parent rock. The conclusion is significant to understanding the essence of Kaiser effect and how to use it to determine the in-situ stress.