The slower response time to the cued than uncued target refers to inhibition of return. It has been always questioned which process is inhibited by the inhibition of return. This study sought to answer this question by using the psychology refractory period paradigm. A visual cue was presented at the cued or uncued location first, which was followed by an auditory and a visual target. Results demonstrated no significant different between the reaction time to the cued that uncued target in short time intervals. But, a significant difference was observed between the response time to the cued than uncued target when time interval was long. Finding suggest that the inhibitory effect might affect the sensory/perceptual stages of processing while eyes are fixated, and the inhibitory effect can be absorbed into the cognitive slack.