Lexical competence is considered as an important indicator of language proficiency. While learning vocabulary, learners need to remember various aspects of knowledge about the word (e.g., meaning, form and use). Many vocabulary learning strategies have been proposed to help learners consolidate vocabulary knowledge. Among them, grouping words belonging to the same meaning categories is conducive to recall (Schmitt, 1997). On the other hand, learning chunks is also a mnemonic device for increasing vocabulary. Taking into consideration these two important vocabulary memory strategies that help students learn faster and recall better, the current study proposes grouping and learning lexical phrases sharing semantic equivalence but differing in use (i.e., phrasal paraphrases) (e.g., "is worth reading", "is worthy of being read" and "is worthwhile reading"). For this, a corpus-based paraphrasing system, PREFER, was introduced because it provides a sufficient number of paraphrases and corresponding Chinese translations, usage patterns and example sentences. Such information could widen and deepen learners' vocabulary knowledge. A pre-and post-test was conducted on 49 college freshmen to examine their performance in phrasal paraphrase learning. The results showed that with the assistance of the introduced system, students achieved substantial gains regardless of their proficiency level. Furthermore, students' errors on the test sheets were thoroughly analyzed for the purpose of understanding students' learning difficulties while learning paraphrases. Despite its exploratory nature, the current study shed some light on the effects of learning phrasal paraphrases on vocabulary expansion.