Abstract: On a dynamic perspective,this paper examines the change of suppliers' perceived relational risks from the TSIs in the relationship with their manufacturers and investigates the moderating effects of contracts and relational norms on the perceived relational risks during the process of manufacturer-supplier relationship development.Through researching on the data from 261 supplier enterprises in Chinese household electrical appliances sector,the hypotheses are tested by using the factor analysis and multi-regression analysis.It argues that(1) Each relationship phase differently moderates the positive relationship between suppliers' TSIs and their perceived relational risks.(2) Although contracts and relational norms both have negative moderating effects on the positive relationship between suppliers' TSIs and their perceived relational risks,these moderating roles are different in various phases of a relationship.The research has drawn both the theoretical and managerial implications for understanding the changing of suppliers' perceived relational risks with TSIs involved in different relationship phases and the differences of moderating effects of contracts and relational norms on the positive relationship between the suppliers' TSIs and their perceived relational risks.

Key words: supplier’s TSIs, relational risks, relationship phases, control mechanisms