The model of the influence of comment media richness and comment emotional intensity on comment usefulness was constructed, and the mediating role of online interaction was explored. Using 2,923 online reviews of notebooks in Jingdong platform, the findings show that (1) review media richness, sentiment intensity and online interaction can promote the usefulness of reviews; (2) review media richness has an effect on review usefulness directly and indirectly through online interaction; online interaction plays a fully mediating role between the effect of sentiment intensity on review usefulness.