The present study investigated whether the attention to and processing of expression modulated the event-related potentials (ERP) elicited by face. In two experiments, a total of 24 adult participants performed go/no-go tasks where the target was defined by the facial expression (smile/anger) or by the person identity (male/female). Two experiments differed only in the response time limit. Results in the experiment with a severer limit showed that the no-go-trial-ERPs between 230-300 ms after the stimulus onset were more negative than the go-trial-ERPs, and this difference was larger when participants processed person identity than when they attended to facial expression. This suggested that emotional information could alter the neuronal activities involved in response inhibition processes.