This study investigated the difference in language proficiency between tribal and nontribal indigenous children after implementing the Montessori language education. Quantitative data were collected and analyzed. The research participants were 39 indigenous children (age: 5 ~ 6 years) from two indigenous preschools in Taiwan: a tribal preschool (19 students), and a nontribal preschool (20 students). The results show that (1) the students from tribal class progressed significantly in their listening vocabulary and reading comprehension, (2) the students from nontribal class progressed significantly in their listening vocabulary and reading comprehension, (3) the students in the nontribal class performed significantly better in language proficiency. Thus, implementing the Montessori language education enhanced the participants' listening vocabulary and reading comprehension.