In this study, people's expectancy value is measured by ”Expectancy Theory.” The interactive behavior in blogs is divided into two modes: ”human-message interaction” and ”human-human interaction.” Satisfaction after using the blogs will be scrutinized through ”Uses and Gratifications Theory.” The findings of our research indicates that the higher the ”perceived reward” and ”preference valence” that people hold for blogs, the more they are willing to engage in interactive behaviors such as ”human-message interaction” and ”human-human interaction” through blogs. In addition, the study also found that the higher the extent of interactive behavior, the higher the satisfaction is. However, bloggers' ”perceptive ability” in blogs has no bearing on their use of blogs, that is, there's no connection between ”perceptive ability” and gratifications.