This study presents a sociolinguistic analysis of a Korean-English bilingual child's code-switching practices from the perspective of language socialization. The ethnographic description and discourse analysis of a migrant Korean family's interaction in the US home shows how the social meanings of languages and language ideologies present within the family's language socialization context were brought into play through code-switching practices. This analysis illuminates the relation of the bilingual child's language socialization practices in his home to the shifts in tones of voice and speech acts in his code-switching, through which he evokes different stances and personae in English and Korean. In this regard, the code-switching practice is a creative linguistic performance co-constituted by the agency and language ideologies enacted in his home context. The language socialization framework in this study provides richer contextual information for the interpretation of complex social meanings of bilingual children's code-switching and agency.