Abstract: Purpose/Significance Under Web 2.0, Vlog, a new form of short video UGC, has developed rapidly with authenticity and diversity, effectively promoting the social interaction between users and the activity of the platform. Previous studies on Vlogs discuss Vlog sharing motivation and the impact of post-dissemination. However, not all Vlogs have significant dissemination effects on social platforms for mass information dissemination, few studies focus on the influencing factors of Vlog popularity. Design/Methodology This paper focuses on Vlog’s video characteristics (video duration, video quality, bullet screen screar number) and Vloggers’ characteristics (expertise, personal reputation, and personal level), and proposes a research model based on signal theory. 18 431 Vlog data was crawled from the Bilibili, and the model was examined by empirical analysis. Conclusions/Findings The results reveal that video duration has a negative effect on Vlog popularity, video quality, bullet screen screar number, expertise, and personal reputation have a significant positive effect, while the hypothesis that the personal level has a positive effect on Vlog popularity is not supported. The paper enriches the current studies on Vlog popularity, and provides relevant suggestions for individuals and platforms to improve the effect of Vlog dissemination.