In this paper, the role of radical awareness in Chinese character reading development among young Chinese-as-a-second-language (CSL) learners is evaluated in terms of a structural property of the writing system: the distribution of elementary, one-radical (i.e. one-element) simple characters as against majority, multi-radical compound characters. Radical awareness, that is, sensitivity to and use of linguistic information contained in compound characters' constituent components (radicals), is known to facilitate character reading, but the specific structural property just mentioned, the distribution of simple and compound characters, has not been adequately investigated. In this study, 142 senior-primary-school CSL learners' character reading ability and radical awareness were assessed (Time 1) and their compound character reading reassessed a year later (Time 2). Controlling for the effect of simple character reading, it was found that radical awareness uniquely predicted compound character reading at both Time 1 and Time 2, but not its development at Time 2 when previous competency at Time 1 was also controlled. A path model depicting the role of radical awareness in character reading development was constructed, and fit well with the data. The findings suggested that CSL learners would benefit from a systematic literacy program reflecting this structural property of the script.