This study is an investigation of the contribution of morphological awareness in Chinese-English biliteracy acquisition. Comparable tasks in Chinese and English were administered to test children's skills in morphological awareness, phonological awareness, oral vocabulary, word reading, and reading comprehension. The results showed that after the effect of Chinese-based predictors had been accounted for, English morphological awareness of compound structure still contributed to variance in both character reading and reading comprehension in Chinese. This finding indicates a cross-language morphological transfer in acquisition of two distinct writing systems. The transfer from English L2 to Chinese L1 is due to the bilingual children's rapidly increasing English L2 skills in their primary school years.