This study investigated the effects of L1 processing experience on L2 morphological awareness. Preliminary cross-linguistic comparisons indicated that morphological awareness in two typologically distinct languages, Chinese and English, differs in several major ways. Based on the comparisons, three specific hypotheses were formulated: compared with learners with a typologically similar L1 background, Chinese learners of English as an L2 would be less sensitive to intraword structural salience, less efficient in structural analysis, and more adept at integrating word-internal (morphological) and word-external (context) information. These hypotheses were tested empirically with two groups of adult L2 learners of English with contrasting L1 backgrounds (Chinese and Korean). The data demonstrated that virtually no difference existed between the two ESL groups in their intraword structural sensitivity, and that, although Chinese learners were notably slower than Korean learners in performing intraword structural analysis, they were far more efficient in integrating morphological and contextual information during sentence processing. Viewed collectively, these findings seem to suggest that L1 processing experience influences the development of L2 morphological awareness in specific and predictable ways.