Service quality becomes the key bottleneck of the adoption of G2B e-government services. In this context, control is an important tool for e-government service providers to direct and coordinate the service process. Based on the control theory, we develop a conceptual model to understand how different control initiatives influence the service quality of G2B e-government services. A multi-method analysis combining qualitative and quantitative analysis was used to conduct the study. Through a case study of a typical G2B service provider, we identified important components of input control and process control and established the conceptual model. Then we tested the proposed model on the survey data from G2B service employees using structural equation modeling. The results suggests that customer-oriented training, service skill training and work motivation as input control initiatives significantly impact the service quality. Besides, coproduction with customers and internal supervision as process control initiatives also have a positive effect on service quality. Improved service quality ultimately predicts the performance of G2B service employees.