There are arguments from theories and empirical evidences whether reward systems can improve signifieantly knowledge sharing activities in enterprise. Based on the perspective of interaction between extrinsic motivation and intrinsic motivation, we develops a theoretical frame to understand how the reward systems to motivate knowledge sharing activities in enterprise, which is supported significantly by empirical evidences. The research results shows that intrinsic motivation is the main force to improve knowledge sharing, and the magnitude and direction of motivational effects from extrinsic ...