In B2B context, the customers of certification industry are taken as investigation object, the service quality’s impacts on relationship quality is explored in this paper. On the basis of existed research, four dimensions of service quality and three dimensions of relationship quality are defined and the model of the service’s impact on relationship quality is constructed. An empirical research based on 721 customers of certification industry shows that process service capability impacts on relationship quality significantly, result quality impacts on cooperate and adoption of relationship quality significantly, whereas it has not significant impact on atmosphere. Process interactive quality and potential service capability have no significant impact on the relationship quality.