How constituent concepts of a compound concept are put together for meaning construction is an important question in cognition. Using English noun-noun compounds with a modifier+noun structure, researchers have observed relation priming between compounds that share the same relation (snowball vs. snowman) compared with those that do not (snowball vs. snowshovel), suggesting explicit use of relation information during comprehension of compound expressions. The present study examined the temporal characteristics of relation priming with event-related potentials. Participants were presented with lists of two-character noun+noun Chinese compound words and judged whether each was semantically meaningful or not. About 260 ms following word presentation, the semantic N400 response was significantly reduced if a word was preceded by a prime with the same first character, indicating semantic processing of constituent morphemes. However, N400 was not modulated by manipulation of relation priming until around 340 ms. Results confirm the use of relation information in semantic composition, but more critically provide the first piece of evidence that compound word comprehension involves serial processing where constituent morphemes are activated in stage one and bound by their relation in stage two. Copyright © 2013 Elsevier Ltd. All rights reserved.