Efficient Chinese character reading requires rapid access to orthographic representations of radical form and position. This study identified the temporal sequence of radical form, radical position and lexicality processing in adult first language (L1) and intermediate second language (L2) Chinese readers. Event-related potential responses in a one-back repetition detection task were submitted to linear mixed-effects models. Violation of radical position produced P100 effects that were left-lateralized for L1 readers and right-lateralized for L2 readers. When controlling for P100 activation, radical position produced a left-lateralized effect at the N170 for L2 readers but no additional activities for L1 readers. Radical form effects were found at the N270 for L1 readers, where radical form violation produced larger N270. Results suggested that radical representations are position-specific in initial orthographic processing for both groups. However, different temporal dynamics and topographic distributions suggested divergent radical processing for native versus non-native readers from the beginning.