Anti-money laundering is a pressing issue in today’s economy. With the newly launched Chinese anti-money laundering regulation, this issue has drawn more and more attention from governments, financial institutions, and scholars. However, there exist many problems in the Suspicious Activity Reports (SARs), large-value reporting, delivering and analyzing processes. In order to further enhance financial supervision efficiency, this paper aims to find out the constraints for AML business in China. After semi-structured interviews with financial institutions and government agencies, we describe the business process in China in the process of dealing with SARs and large-value reports based on Theory of Constraints (TOC). We then extend our research by a comprehensive field study, and find that the main constraints for financial institutions are the incapable SARs extracting system, the immature AML internal control mechanism, the changing AML administrative rules and regulations, the prob...