Purpose: This study aims to investigate how brand-related user-generated content (UGC) influences consumers' brand attitude and behavioral intention in the context of the Metaverse, and the mediating role of virtual brand experience, perceived information usefulness, perceived interactivity, and attitude toward advertising. Research design, data and methodology: The study was conducted using a survey with 239 questionnaires from frequent social media users in China and hypothesis testing through AMOS 26.0 structural equation modeling. Results: The findings suggest that (1) brand-related UGC positively influences brand attitude and behavioral intention through virtual brand experience, perceived information usefulness, perceived interactivity, and attitude toward advertising. (2) The study identified the fully-mediated effects of virtual brand experience, perceived information usefulness, perceived interactivity, and attitude toward advertising in the impact of brand-related UGC on brand attitude and behavioral intention. (3) The mediating pathway with the most significant impact on behavioral intention was the virtual brand experience and attitude toward the advertising, followed by the effect of the virtual brand experience, perceived information usefulness, and perceived interactivity on brand attitude. Conclusions: This study presents UGC as a new type of digital promotion that can positively impact the effectiveness of brand advertising in the Metaverse.