Abstract
　This is a review of precursory phenomena observed in rock fracture laboratory experiments for the purpose of earthquake prediction. A particular attention is paid to the source process of acoustic emissions and the dynamic properties of stick-slip motions in a rock specimen in relation to earthquake faulting. Although our knowIedge about the effect of size in space and time on rock properties is limited, laboratory experiments and theoretical studies on time dependent properties of rocks are most powerful to develop the theory of earthquake prediction. It is further concluded that the detailed structure of strength distribution on a pre-existing fault plays an important role in governing most of precursory phenomena and high-frequency behaviour of earthquake fau1ting.

*東北大学理学部
Faculty of Science, Tohoku University