Abstract: Delexicalization is a very common language phenomenon and "thing" is considered to be one of the frequently-used delexicalized words. Chinese learners' use of "thing" was investigated using the two corpora WECCL (Written English Corpus of Chinese Learners) and NESSIE (Native English Speakers' Similarly-and Identically-promoted Essays). The results indicate that Chinese learners tend to overuse the word compared with native speakers. Meanwhile, there are a large number of improper uses of "thing" such as redundance, substitution, collocation and semantic errors. However, the frequency of the use of the word and such errors significantly declines with the improvement of the learners' language competence, which is in conformity with the development pattern of interlanguage. The overuse and improper uses of "thing" might be attributed to the learners-limited lexical competence and learning strategies as well as the effects of language negative transfer and the psychological mechanism of interlanguage.