Indonesia is one of the developing countries with the increasing of elderly population. Number of elderly in Inoinesia in 2011 amounted to 16.5 million people of the total population of over 220 million people, including those are still potential, and the amount is increases year by year. Elderly people who are still productive which can be directed is a huge potential market in productive economic activity. A phenomenon that occurs at this time in Bandung itself, is Day Care for elderly that are still very rare. Mostly, day care are allocated for the toddlers (children under five year ). The draft will be made according to the Kotler and Keller theory (2012) and other theory that related to marketing mix and buying interest. Data sources are data primary and secondary data. Data acquisition will be done through an interview, observation and questionnaires. Where the purpose of this research is to look for which marketing mix that affecting buying interest.Result of the study was the Marketing Mix Effect on buying interest can be concluded into Product, Price, Place and People which influence the buying interest in day care home service.