Along with the growing era, everything can be searched quickly through the help of technology, including the trend that is enlivened by women today, which is about makeup. The purpose of this research is to know the positive influence of electronic word-of-mouth in an online beauty forum Female Daily Network to consumer’s purchase decision of Maybelline Magnum Barbie Waterproof Mascara product. This research is using a quantitative model by distributing questionnaires online to as many as 96 female respondents who are the members of the Female Daily Network forum by using simple random sampling method. Research of the data analyzed using the simple linear regression analysis and hypothesis testing done by using the significance Z-test. The results of this research shows that there is a strong positive influence of electronic word-of-mouth in the Female Daily Network forum on consumer purchasing decisions of Maybelline Magnum Barbie Waterproof Mascara products.