This paper explores five social media's media ecological location in the social user through niche analysis of five key SNS services (Facebook, Instagram, YouTube, Pinterest, and Twitter). Based on the results of 224 SNS user's questionnaire, factor analysis was carried out to extract five common factors of relationship, sociality, convenience, routine, and entertainment. The results of the niche analysis showed that Facebook had the widest niche in sociality (.627) and convenience (.636), and YouTube showed the widest niche in routine (.670) and entertainment (.615). For relationship (.520), Instagram had the widest niche. In terms of five factors, Facebook and YouTube have the greatest overlap in relationship (1.826) and sociality (2.696), while Pinterest and Twitter had the biggest overlap in routine (1.937); entertainment (2.263) and convenience (2.583). Besides, YouTube and Twitter had the most overlap. Facebook, Instagram, and YouTube had a competitive advantage over Pinterest in terms of all factors.