This study aims to investigate the lexical combination and errors in Korean university students’ English composition corpus. The result shows that Korean university students frequently use nouns, lexical verbs, articles, prepositions, adjectives, adverbs, to infinitive, be verbs, personal pronoun, coordinating conjunctions, subordinate conjunctions, have verbs, and do verbs in their English writings. Moreover, in the use of lexical combinations of the four different genres of English writings, the noun and verb combinations show most frequent, yet the adjective and adverb or adverb and preposition combinations are less frequent. As a result of an analysis of word combination errors, word selection errors are relatively frequent compared to the word omitting errors. Based upon such findings, this study will provide effective ways to make collocational lists based on the learner-made collocational errors and help raise awareness of English collocation teaching in Korean EFL classrooms.