The temperature dependence of Portevin-Le Chatelier (PLC) effect in a nickel base superalloy was investigated. A series of tensile tests were conducted ranging from room temperature to 900℃ at a constant rate 5×10^-4 s^-1. The critical strain,amplitude of stress drop, waiting time and flying time of serrated flow were analyzed in order to reveal the temperature dependence of PLC effect and its related micro-mechanism. The results showed that the normal behavior occurs as temperature changes from room temperature to 450℃, in which the critical strain of serrated flow decreases with increasing temperature while magnitude of the stress drop increases. The normal PLC effect is mainly controlled by pinning effect of solute atoms and its diffusion process. When temperature increases from 450℃ to 600℃, the critical strain of PLC effect increases and the inverse PLC effect appears. Since some dislocations are pinned by solute atoms prior to breakaway, the dominant factor of inverse PLC effect is that pinned dislocations get rid of solute atoms and move freely. With temperature increasing above 600℃, PLC effects disappear because it is difficult to form effective solute atmosphere necessary to lock mobile dislocations.