The research objective is to investigate the effect of brand equity on Thai cosmetic purchasing decisions. The study involved 500 individuals aged 20-59 who had purchased and used Thai cosmetic products within the past year. A multistage sampling method was employed to select the participants. Data collection was carried out using questionnaires, and both descriptive and multivariate statistical analyses were conducted, explicitly utilizing Second-order Confirmatory Factor Analysis and Structural Equation Modeling. The research results showed four factors influencing the purchasing decisions of Thai brand cosmetic products: Brand Equity, Buying Behavior, Consumer Satisfaction, and Perceived Value. The Second-order Confirmatory Factor Analysis and Structural Equation Model demonstrated that these factors met the assessment criteria when applied to the empirical data. Consequently, if a brand can establish brand equity that surpasses its competitors in the eyes of consumers, it will contribute to long-term profitability and sustained growth.