Grammatical metaphor is an important feature of academic discourses. This study selected the English abstracts published in a Chinese academic journal and a foreign one concerning marine science and established two corpora. Based on the Systemic Functional Linguistics, thirteen kinds of grammatical metaphors in the two corpora were identified and calculated. The statistical results showed that the two corpora contained a large number of grammatical metaphors, especially the kinds No. 1, 2, 5, 6 and 13. But in terms of the frequency, the two corpora had a clear difference. Abstracts in the foreign journal contained more grammatical metaphors than those in the Chinese one. This partly reflects some differences between Chinese researchers and foreign ones in the English writing. The results also give us some hints on how to carry out the ensuing longitudinal research concerning the development of English writing of Chinese students under the framework of Systemic Functional Linguistics.