This study was conducted at Losari Beach Makassar South Sulawesi province with the objective to analyze the social interaction of the street vendor in Losari Beach, which is associative and dissociative.This research was a case study (case study) arguing that this research was specific to describe clearly the meaning of phenomena that occurs. This study also used naturalistic paradigm approach (qualitative) to analyze and to construct the street vendors as an actor directed social interaction to get data from the street vendors who are associative and dissociative based on empirical facts in Losari Beach Makassar. Data analysis was performed with data reduction that is focused on the election, simplification, abstract, and transformation of raw data from field notes, followed by the presentation of the data and drawing conclusions. Research showed that social interaction of the street vendor at Losari Beach, which is associative is manifested in the form of cooperation, accommodation and assimilation. Social interaction of the street vendor at Losari Beach, which is dissociative is a form of social interaction are embodied in social processes between individuals or groups of street vendors with buyers or consumers, between the vendors with coastal managers of Losari Beach. Social interaction dissociative includes competition, contention (conflict), and contravention. The social interaction that is dissociative at Losari Beach in the form of competition is a social process that arises as a result of price competition, the quality of goods or merchandise, cleanliness, and others to attract interested visitors or customers at Losari Beach. It can be said that social interaction is increasingly open to serve as a place of business that can provide economic benefits for street vendors (PKL) at Losari Beach in Makassar South Sulawesi province.