Abstarct: Brand is an integral part of the company's marketing strategy; it is increasingly considered as the only important asset and source of differentiation. Thus, strong brands offer more profit with less risk to shareholders. Successful brands increase consumer trust in intangible products and services, and customers are able to better visualize and identify their services. The retail industry in the form of chain stores is one of the most important industries in the supply chain of any industrial and manufacturing company, especially in the field of consumer goods. One of the most important characteristics of the current environment of this industry is the increasing competition that is observed every day with the emergence and development of new competitors in this industry. The direct result of this situation is the necessity and serious attention in using effective mechanisms to maintain and improve customer satisfaction and to as a result, sales through quality are a part of services and create more value for customers. The goals of this research are to analyze and evaluate the store brand on the behavior of customers in chain stores and to identify the effective criteria for choosing the brand and to evaluate the importance and weight of each of the effective criteria. To evaluate and rank the criteria, the new multi-criteria Pythagorean fuzzy AHP method was used According to the calculations made in this research, the criteria were prioritized baxsed on weight in the order of environmental factors, economic factors, fundamental factors, social factors and individual factors. baxsed on the sub-criteria, the price and product quality variables have the highest weight, and then the brand reputation, the customer's mental image of the store and easy access. And the lifestyle variables, recommendations of others, and advertising were less important.