Recent second language (L2) reading studies have examined how characteristics of an individual learner and word-specific linguistic properties jointly predict successful L2 word-meaning inference, i.e., a learner's ability to guess the meaning of an unknown word. Semantic transparency is one such word-specific property. Each constituent morpheme in a compound word contributes differently to the word's overall meaning. As a result, words vary in the degree to which they are transparent or opaque. The ability to infer the meanings of these compounds is associated with broad linguistic knowledge that varies greatly across learners. This study explores how L2 linguistic knowledge as an individual learner factor and semantic transparency as a word-specific property interact to affect L2 learners' word-meaning inference in Chinese. Two hundred and twelve adult L2 learners of Chinese in China completed six paper-pencil tasks, which measured participants' short-term memory, linguistic knowledge, and meaning inference of compound Chinese words that varied in their semantic transparency. The results showed that linguistic knowledge interacted with semantic transparency in word-meaning inference: morpheme knowledge and grammatical knowledge were significant contributors of word-meaning inference only for transparent words when L2 learners' short-term memory was controlled. These findings underscore how reading in an L2 involves the interplay between the learners' characteristics (e.g., linguistic knowledge) and language-specific properties (e.g., semantic transparency).