The purpose of this study is to develop the scale for diagnosing elementary school children's online game addiction through a scientific development process. The pilot test was conducted three times, and items analysis, reliability analysis, and factor analysis were conducted in each test, so 30 questions were decided for the main questionnaire survey. Some referential variables were included in the questions for the main survey such as items for testing the actual use condition and attitude of online game, aggressive behavior, impulsive behavior, solitude and self-control. In the main survey, a total of 2,584 fifth and sixth-grade students participated. For the results of the main survey, item analysis and reliability analysis were conducted, and validity was tested by exploratory factor analysis and correlation analysis. Finally, the final questions and the grouping criteria were developed through the standardization process.