As increasing the rates of purchasing cosmetic in internet shopping mall, the relationship marketing between purchaser and shopping mall service providers has become more important. At this point, the purpose of this study was to investigate factors of relational benefits and commitment, and to analyze the effects of relational benefits and commitment on word-of-mouth intention and repurchase intention for cosmetic purchaser in internet shopping mall. With convenience sampling, the research was surveyed to 20’s to 30’s female and male who had purchased cosmetics in internet shopping mall. The 308 responses were analyzed by frequency analysis, factor analysis, reliability test, and multi-regression analysis. The results were as follows. First, the factors of relational benefits were divided into psychological benefits, social benefits, and economic benefits. Also the factors of commitment were divided into calculative commitment and affective commitment. Second, only psychological benefits affected to calculative commitment, and all three factors of relational benefits affected to affective commitment. Third, the word-of-mouth intention for cosmetic purchaser in internet shopping mall was affected by psychological benefits, social benefits, economic benefits, calculative commitment and affective commitment. Lastly, the repurchase intention of cosmetic in internet shopping mall was affected by psychological benefits, social benefits, economic benefits, calculative commitment, affective commitment and the word-of-mouth intention.