eWOM is one of the most important channels for consumers to gain knowledge on products, and is more reliable than marketing information provided by corporate. The previous studies on eWOM mainly analyzed the effect of eWOM valence and variance on consumer decision making. They also have considered variables such as product type and cultural difference that moderate the eWOM and sales. However, there is limited research that examines the moderating effect of the eWOM of rival product. This study we examined the impact of eWOM valence and variance on sales in movie industry, and analyzed the moderation effect of eWOM of rival movies between eWOM and movie sales. We collected data for 45 days in 112 movies in Korea, and analyzed 4,487 data through multiple regression analysis. As results, the eWOM valence and variance have positive effects on movie sales. In addition, the positive eWOM valence effect of rival movies weakened the positive eWOM effect on movie sales. On the other hand, the positive eWOM effect on movie sales increased as rival movie number increased.