Action research was applied to this study. The subjects were one third grade class of an elementary school, totaling 23 students. The multicultural education that integrated an inquiry teaching model that incorporates indigenous legends with mathematics and science concepts was designed to explore the students' mathematics and science achievements and cultural learning. The teaching team implemented the teaching model in 4 class sessions per week for a total of 7 weeks. The qualitative and quantitative data were collected from mathematics and science achievement tests, culture learning scale, class dialogues, teaching reflection journals, and teaching feedback of teachers and students. The results showed that the mathematics and science achievement, ethnic identity, and cultural appreciation of the students significantly improved. The professional growth of the teaching team included: confirming that indigenous culture can serve as a teaching resource in mathematics and science subjects, verifying that inquiring teaching should include the processes of both invention and discovery, and discovering that multicultural teaching should include both ethnic identity and cultural appreciation.