This study focuses on identifying young learners’ vocabulary mastery after the activity of the dice game and indentifying the strengths and weaknesses of dice game  activity  in  enhancing  young  learners’  vocabulary  mastery  in  learning English. This research is a classroom action research for the fifth grade of MI Miftahul Ulum Karangmojo in the Academic Year of 2015/2016 which consisted of three cycles. There were two kinds of this research data, namely qualitative and quantitative, which were collected by using test, questionnaires, interviews, observation, and documentation. The results of this study show that: (1) the dice game activity enhances the young learners’ vocabulary mastery, (2) there are some strengths and weaknesses of dice game activity in enhancing the young learners’ vocabulary mastery in learning English