ISPR, International Standard Payload Rack, is a facility class payload for space station science operations and is interchangeable among the NASA, ESA and NASDA laboratory modules with common resources. The ISPR structure has been developed and qualified as a primary structure of ISPR, having a structural capability of supporting internal payloads for launch/landing/on-orbit events and compatible mechanical interfaces between international laboratories. Features of this ISPR structure are light weight using high strength aluminum alloy for main structural members, easy access by large detachable panels, flexible volume for users without any additional reinforcements for the maximum loading conditions and multiple launch and landing operation capability.