Emotion, as an important aspect of human intelligence, has been playing a significant role in virtual characters. We propose an improved three-level structure of affective model as "personality-emotion-mood" for intelligent and emotional virtual characters. We also present the emotion state space, as well as the emotion updating functions, to generate authentic and expressive emotions. In order to achieve the complexity and variety of behaviors, we bring forward a behavior organizing structure as the behavior tree, which defines four kinds of behavior organizations as well as the behavior tag and behavior message, to manage virtual characters' behaviors. At the end, we achieve an experimental platform BAAP, which prove our emotion model and behavior organizing structure to be effective and practical in generating intelligent and emotional behavioral animations.