Objective: This study aims to examine the influence of sales service factors on customer purchasing behavior at the Win Commerce retail chain. Theoretical Framework: The research is grounded in consumer behavior theory and the various factors that influence purchasing decisions Research Methodology: Authors surveyed 300 actual customers who had made purchases at Win Mart and Win Mart+ stores in Hanoi. The collected survey data were analyzed using SmartPLS software. Results and Discussion: The findings reveal that three out of six factors included in the model significantly influence purchasing behavior. Among these, the factor "Product Pricing" (GC) has the strongest impact, followed by "Value-Added Services" and "Store Branding". The remaining three factors—"Technology," "Customer Service," and "Convenience"—do not show statistically significant relationships with customer purchasing behavior at Win Commerce stores. Research Implications: Based on the analysis results the author proposes several recommendations to enhance the shopping experience and strengthen the company’s competitive position, thereby encouraging customers to shop more frequently at the supermarket chain.