Radicals are building blocks of Chinese complex characters and exhibit certain positional, phonological and semantic regularities. This study investigated whether adult non-native learners of Mandarin Chinese as a foreign language (CFL) were aware of the positional (orthographic), phonological and semantic information of radicals, and whether such radical sensitivity was predictive to their Chinese word reading abilities. Eighty-four CFL learners were administered a picture-character mapping task in the no cue, phonetic cue and semantic cue conditions, along with two character reading aloud tasks. CFL learners tended to choose the options of correct radicals in correct positions more than the ones containing correct radicals in incorrect positions when no cue was provided. A semantic radical bias was observed in both the no cue and semantic cue conditions: CFL learners chose semantic radicals in correct positions more than phonetic radicals in correct positions. But the pattern was reversed when phonetic cue was provided. In addition, radical sensitivity uniquely predicted CFL learners' word reading even after controlling for years of learning Mandarin Chinese. Results showed that CFL learners employed orthographic, phonological and semantic information of radicals in encoding novel characters in a manner largely similar to that of native Chinese readers.