The effect of concreteness has been heavily studied on nouns. However, there are scant reports on the effect for verbs. The present research independently manipulated concreteness and word class of Chinese disyllabic words in tasks that required different depths of semantic processing: a lexical decision task and a semantic relatedness judgment task. The results replicated the concreteness effect for nouns, indicating that concrete nouns elicited larger N400 responses than abstract nouns with a broad distribution over the scalp, irrespective of the task demands. Similar to the findings from English unambiguous verbs, the concreteness effect for Chinese verbs was also robustly observed from fontal to posterior electrodes in both tasks. These results suggest that when Chinese nouns and verbs are typical and unambiguous in both meanings and word classes, the similar topographic distributions of the N400 components reflect the same underlying cause(s) of the concreteness effect for these two word classes.