This study aims to describe and explain the process of improving the implementation of learning mathematics through Learning Model Team Games Tournament ( TGT ) to increase interest and class III student achievement MI Muhammadiyah Ngadipuro 1 Dukun, Magelang . The research was conducted in the form of action research that consists of two cycles. Subjects were grade III and this is the object of interest and study mathematics achievement through learning models Team Games Tournament. Data collection techniques using interest questionnaire sheet, observation sheets interests and achievement tests. Test instrument covering the validity and reliability testing. From the research that has been done shows as follows. First cycle test results indicate an improvement when compared with the initial values of students. The average initial value was 49.7 students increased to 57.5. Second cycle test results indicate an improvement when compared to the test cycle I. The average value of the first cycle is 57.5 increased to 67.5. It can be concluded that the interests and achievements of students studying mathematics class III MIM Ngadipuro 1 Dukun, Magelang increased .