People often fail to see salient but unexpected objects in absorbing tasks. The present study was aimed to investigate the role of inhibitory mechanism for such attentional lapse. By manipulating similarity between distractors and unexpected objects, the first experiment shows the effect of inhibition in affecting the possibility of blindness. By reducing the number of distractors, the second experiment further suggests that there are different levels of inhibition. The two experiments together support the idea that inhibition on distractors as an attentional control influences the notice of unexpected objects. The findings provide implications for designing intelligent agents and systems.