The aim of this paper was to examine appropriateness of the means and procedures on negative priming task and concepts on inhibition theory (Tipper & Cranston, 1985). In negative priming tasks, when subjects response a stimulus, which was ingnored in the previous trial, the RTs were significantly delayed. This is familiar enough phenomenon, which was known and described as "negative priming effect". One of interpretations of this phenomenon is inhibition theory. According to this theory, when subjects ignore distactors in N-1 trial, inhibition mechanism keeps the representations of the distractors suppression. Thus, in N trial when subjects response the stumulus which was a distractor in N-1 trial, activation of the representation require time. In this paper, I demonstrated that this theory is circular reasoning.