This paper deal with the characteristics of acoustic emission (AE) signal which generated by friction and wear. The experiments carried out changed the finishing method of plate specimens for produce a typical wear mode. As experimental results, the correlation was observed between the friction and wear phenomena and the amplitude of AE signal or the AE frequency spectrum. The summary of results is shown below. In the abrasive wear mode, wear rate is relatively high, but the AE count rate and the amplitude of AE signal are small. In the adhesive wear mode, wear rate is small, but the amplitude of AE signal is larger. In the abrasive wear and adhesive wear mode, AE signal in the 1-1.5MHz frequency spectrum band was observed.