Compared with event-related potential (ERP), which is widely used in psychological research, functional near-infrared imaging (fNIRI) is a new technique, and can supply hemodynamic information related with brain activity, excepting for electrophysiological signals. We conducted a series of experiments with the classic paradigm of ocular nonselective attention, monitored responses if brain with fNIRI and ERP respectively, and then analyzed the data. The results showed us that ocular nonselective attention companied activation was on the prefrontal lobe, which had the same results as its related P3a in ERP. In fact, the fNIRI results demonstrated a smaller area of the source than ERP, which was at the middle part of Brodmann 46, and the phenomenon that the hemodynamic activation occurred before P3a and strengthened just after P3a, supported the possibility of further study in brain mechanism. Therefore, fNIRI is a potential technique in advanced function research of brain.