Nowadays, many facilities of banking enterprise being increased. This condition support information technology (IT) of banking become sophisticated. SOme new systems emerge as important system in banking business activity, such as Core Business SYstem, Internal Support System, End User Computing, System Integration, Asset Product, Payment System, and Delivery Channel. Each system have different platform function, so it cause many potential problems in IT banking business system. For example, variety of communication format in every system cause architecture of system become complicated every time. Base on this condition, need analysis to decrease these effect. Here, Enterprise Service Bus (ESB) choose as one of analyze method, because ESB have some advantages, simple and efficient. More specific, in this analyze method done by measuring modularity of ESB architecture system and recent banking architecture system. Both, calculate using SIngular Value Modularity Index (SMI). Range of SMI index is 0-1, were 0-0,5 is classed into integral, and 0,5-1 is modular. The result of these calculation, show that ESB banking architecture system is quite higher than recent banking architecture system. Its mean that using ESB can improve technical efficiency and flexibility of these systems. Although ESB more efficient and flexible than recent banking architecture, but both architecture systems not only analyze from business view side, but also in technical view. The measurement result SMI index which have done indicate that the value is smaller compared to the recent one. This is prove with ESB technology, the architecture will be more efficient progressively form technical side but remain to maintain flexibility of architecture with concept form ESB technology. Key words: Arsitecture, Enterprise Service Bus, SIngular Modularity Index, Modularity