Background: Previous work suggests that children can teach themselves new written words via reading aloud texts independently (i.e., orthographic learning via self-teaching). In self-teaching in Chinese, regular phonetic radicals and transparent semantic radicals facilitate orthographic learning. The present study examined the roles of phonetic and semantic radicals in both orthographic learning and oral vocabulary learning via self-teaching among Chinese children. Methods: Thirty-four Mandarin-speaking second graders read aloud and comprehended 12 stories annotated with Pinyin, a phonetic script in Chinese. Each story included a semantic-phonetic compound pseudocharacter appearing five times. The phonetic radicals were classified as one-third regular, one-third semiregular and one-third irregular. These phonetic radicals carried full, partial or no phonetic information, depending on their regularity. Moreover, half of the semantic radicals were either transparent or opaque, meaning that they were semantically related or unrelated to the meaning of the pseudocharacters, respectively. Learning outcomes included participants' oral vocabulary learning and orthographic learning regarding word recognition and spelling. Results: In addition to the well-studied orthographic learning, children can also achieve vocabulary learning via self-teaching. Results indicate that transparent semantic radicals facilitated orthographic and vocabulary learning. Moreover, vocabulary learning was facilitated by regular phonetic radicals but hindered by semiregular phonetic radicals. Conclusions: These findings, together, point to the roles of phonetic and semantic radicals in Chinese children's orthographic and vocabulary learning. Findings advance our understanding of self-teaching across writing systems and add to the educational value of self-teaching.