Event-related potentials (ERPs) were used to investigate the online processing of tone and intonation in Mandarin at the attentive stage. We examined the behavioral and electrophysiological responses of native Mandarin listeners to Mandarin sentences, which contrast in final tones (rising Tone2 or falling Tone4) and intonations (Question or Statement). A clear P300 effect was observed for question-statement contrast in sentences ending with Tone4, but no ERP effect was found for question-statement contrast in sentences ending with Tone2. Our results provide ERP evidence for the interaction of tone and intonation in Mandarin, confirming the findings with behavioral metalinguistic data that native Mandarin listeners can distinguish between question intonation and statement intonation when the intonation is associated with a final Tone4, but fail to do so when the intonation is associated with a final Tone2. Our study extended the understanding of online processing of tone and intonation (1) from the pre-attentive stage to the attentive stage and (2) within a larger domain (i.e. multi-word utterances) than a single word utterance.