The main purposes of this one-year case study are to create learning environments for indigenous students through culture-based mathematics instructional modules, and what teachers' responds are in two tribes. The researcher leads sixteen in-service teachers and seven pre-service teachers to enter two indigenous tribes- "Cado" and "Jayama," and design culture-based math modules for indigenous students of tribal elementary schools. Through five stages of guidance, including "preparation and planning," "exploration and understanding," "reading and design," "comment and revision," and "practice and reflection," the participants work together to develop seven sets of culture-based math modules in total. Based on observation, interview, and analysis of related documents, it is shown that the implementation through culture-based mathematics instructional modules could motivate students' interest in learning math, and enhance their initiatives in the classroom. Hopefully, such cooperation between universities and local elementary schools will lead to improvement in the mathematics learning environments for the tribes.