This goal of this article is to overcome the research gap by developing the basic theory of the service quality in relationship marketing. This article examines effect of strategy of improving service qaulity of B2B sharia banking and culture fit toward customer satisfaction, loyalty and positive recommendation. The study also seeks to demonstrate the interdependence between variables. Convenience samples are 200 respondents: business owners, heads of organizations/companies and financial managers who make use of electronic transactions of BSM Kudus and Pati, whether as a creditor, debitor or other services of BSM. Result of path coefficient analysis shows that the dimensions of empathy, tangibles, reliability, compliance and cultural fit directly or indirectly have effect on loyalty.