Attention is a fundamental function of the human which is important in our daily life. Perceptual load is thought to play an important role in selective attention^1,2^. When perceptual load is high, the distracting information will be kept out of perception and will not affect us. When perceptual load is low, the distracting information will be processed deeply by us and will influence us^3^. However, most of the past research was concerned with binocular attention instead of monocular attention. In spite of the differences such as visual acuity^4^, stereopsis^5,6^ between binocular and monocular vision, there were few reports of their difference regarding to perceptual load which means more items and features in our research. Here we show their difference with the application of perceptual load to a selective attention task adapted from Eriksen's flanker task^7^. According to our research, monocular subjects are more sensitive to perceptual load with a lower perceptual load keeping them from the distracting effect. The difference may be attributed to less perceptual capacity rather than better attention of monocular vision. The research revealed a difference between binocular and monocular perceptual capacity and provides a new perspective to study the neural mechanism of perceptual capacity
