This study analyzed the effects of comic book reading program on Korean proficiency and acculturation of youth with immigration background, by conducting a six-month reading program with five teenagers with immigration background. Ten comic books were selected from <Excellent comic books for children and young adults> published by School Library Journal, based on the themes - that are related to the lives of youth with immigration background - and interests of participating teens. According to the literacy skills test conducted before and after the reading program, the participating teens' Korean proficiency has generally improved, particularly in the areas of interpretation and vocabulary. In terms of writing, grammatically incorrect sentences, phrases, and expressions have declined. Most participants showed stable adjustment to Korean culture, but one participant who felt still insecure of her ethnic identity deeply empathized with one of the characters of the books, and shared the difficulties of living as an outsider of a society. The participants of this research learned or rediscovered the joy of reading through this comic book reading program; at the end of the program, many of them expanded their interest in reading novels, books without any illustrations.