With the modern development of economics and marketing, brands are having a more important role in lives these days. Brands become extremely attractive as the customers feel more confident and think that they have a better quality than other brand. Brand is something unique and serves as a differentiator between one company and another. Inspired by this concept, the purpose of this research is to find out whether and how brand impact customer purchasing behavior on mobile phone at PT Samsung Electronics Indonesia and what factors of brand that influence the customer purchasing behavior.This research is using quantitative research design. The result of the survey shows that there is a relationship between brand and customer purchasing behavior on mobile phone at PT Samsung Electronics Indonesia, Medan. There is a strong positive correlation between both variables and brand can impact 56% of customer purchasing behavior while the rest 44% are affected by other factors. Lastly, the brand factors that influence customer purchasing behavior, which include brand identity, brand awareness, brand loyalty and brand design, where brand awareness play the most important role.