This article provides a systematic account of collocational use in Chinese EFL learners' oral production and explores some of the issues involved, by adopting a corpus-based error analysis approach. The distribution of six types of collocational errors extracted from two sizeable Chinese learner English corpora shows that verb-noun collocations pose the greatest difficulty for Chinese learners. An exploration of the correlation between the learners' English proficiency and collocational performance finds that the learners' knowledge of collocation has not developed alongside their knowledge of vocabulary in general. Our further descriptive and diagnostic analyses of verb-noun errors indicate that 1) Chinese EFL learners have the greatest difficulty with the verbs when using verb-noun collocations; 2) the learners' use of nouns is also not satisfactory; 3) due attention should be paid to the inappropriate use of the non-lexical elements (prepositions and articles); and 4) the main causes of verb-noun collocational errors include L1 transfer, assumed synonyms, overgeneralization and misselection of the target word. It is suggested that university English teaching in China should attach more importance to the examination and diagnosis of collocational errors and also integrate learner-centered, corpus-based methods into vocabulary teaching.