Phonological processing skills predict early reading development, but what underlies developing phonological processing skills? Phonological representations of 140 native Cantonese-speaking Chinese children (age 4-10) were assessed with speech gating, mispronunciation detection, and nonword repetition tasks; their nonverbal IQ, reading, and phonological processing were assessed with standard tests. Results indicated that even without explicit script-sound correspondence at the phonemic level in Chinese orthography, young Chinese speakers developed representations segmented at this level, and such representations were more fine-grained for older children. Further, the quality of kindergarteners' phonological representations (specified by sensitivity to mispronunciation in lexical judgment) significantly predicted their emergent reading abilities, and this relation was fully mediated by phonological processing skills, with rapid naming showing the strongest mediation effect. Such mediation was no longer found with the primary-school sample, suggesting plausible developmental changes in the relations between phonological representations, phonological processing, and reading during early reading development.