This study develops an intercultural and intergenerational model for teaching Mandarin as a second language, aimed at enhancing international students' intercultural communicative competence. Three native Mandarin-speaking kindergarten children in Taiwan, with no English knowledge, participated in a university Mandarin class with international students. They interacted exclusively in Mandarin, engaging in tasks like introductions, surveys, and storytelling. Students later provided community services, reading to Taiwanese kindergarteners in Mandarin. Through action research, including teacher logs, reflections, and interviews, the model was shown to improve students' attitudes, interpretation skills, and critical cultural awareness.