An ERP experiment was conducted to explore semantic and syntactic processes as well as their interplay in Chinese sentence comprehension. Participants were auditorily presented with Chinese ba sentences, which were either correct, semantically incorrect, syntactically incorrect, or both semantically and syntactically incorrect. The syntactic violation, which was created by eliminating the object-noun phrase from a preposition-object phrase structure, elicited an early starting anterior negativity which merged into a sustained negativity over anterior sites and a temporally limited centro-parietal negativity. The semantic violation elicited an early starting N400 effect. The combined violation in which the syntactic phrase structure violation and the semantic violation were crossed elicited an early staring sustained anterior negativity similar to the pure syntactic effect, and a centroparietal negativity which was more negative than those of the syntactic condition and the semantic condition. No P600 was obtained neither for the syntactic nor for the combined condition. The results suggest that the syntactic processes (at about 50 ms) appear earlier than the semantic processes (at around 150 ms). They are independent from each other in the early time window (150–250 ms) but interact in a later processing phase (250–400 ms) during Chinese ba sentence comprehension. The broadly distributed negativity, which occurred during the N400 latency range observed in the three violation conditions, is thought to reflect thematic integration processes in the sentence-final position. © 2005 Elsevier B.V. All rights reserved.