ABSTRAK
The objective of this study is to describe how TPR method can be implemented effectively in improving students’ vocabulary mastery and their behaior when attending the lesson. This action research was held at a State Elementary School Karanganyar for 25 students of grade fourth. It consisted of two cycles. There were five meetings in the first cycle and three meetings in the second cycle. Every cycle consisted of four stages: planning, acting, observing, and reflecting. The technique of collecting data were observation, interview, field note, documentation, and test. The qualitative data were analyzed by using five stages; assembling the data, coding the data, comparing the data, building interpretations, reporting the outcomes. Meanwhile, the quantitative data were analyzed by using descriptive statistics. The result of the study shows that some conditions have to be met for the effective implementation of TPR in improving students’ vocabulary mastery and their behavior when attending the lesson. They are (1) providing clear rules, (2) providing numerous types of drilling activities, (3) providing more writing activities, (4) providing adequate action repetition as a routine (5) providing reward, (6) using encouraging sentences (7) supporting TPR with interactive teaching media. By applying those conditions, it can improve students’ behavior when attending the lesson and their vocabulary mastery in the aspects of meaning, spelling, pronunciation, and grammar. 
Keywords: Vocabulary Mastery, TPR, Class Room Action Research