Indonesia is one of the countries in Asia Pacific with the largest e-commerce growth since 2017. Internet users have reached 63 million, about 95% of social media users. Website is one of the social media used by entrepreneurs for online marketing. Relationship Marketing is the company's strategy to attract purchase intention. MatahariMall.com is one of the O2O based online retailers and provides 2000 Indonesian outlets. Relationship marketing and brand awareness arise in the minds of customers when registering members. Research aims at identify and find the variables that are estimated to build purchase intention customers transact online at MatahariMall.com customers in Malang area. The results showed that the website and relationship marketing has strong and significantly effect on purchase intention through brand awareness. The better quality system website and commitment in relationship marketing built retail website can increase brand awareness built retail website, reflected from brand recognition, customers will remember the retail website because the price of products sold on the retail website is known to be affordable and affect the purchase intention, which reflected in the intend indicators, customers will see the affordable price and quality of products so willing to follow the offer displayed on the retail website and interested buy, then, reflected from the predict indicators of customers, interested to become an active member in the near future.