Tower Defense (TD) game has always been a very popular video game. The purpose of this study is to explore the attractive factors of TD games and the relationship between these factors. The evaluation grid method was used to find the attractiveness of TD game, and the quantification theory type 1 was applied to get the influence weight between these elements. The results show that there are four main charm factors in TD game: sense of control, sense of challenge, sense of urgency and Sense of enjoyment. The quantitative statistical results show the weight relationship between the attractive factors. The results can be used as a reference for game developers.