A proto type comprehensive foundation design code which can harmonize all the major foundation design codes in Japan is proposed in this study. This study is much motivated by the rapid development and popularization of the limit state design based design codes in the world, including ISO2394 and Eurocodes, as well as of the performance based design concept especially after the conclusion of WTO/TBT agreement in 1995. In proposing the code, it is much contemplated to propose a concept which can harmonize all the major Japanese foundation design codes that have been developed rather separated way due to many historical reasons. A comprehensive design code is a concept we proposed to achieve this aim. By doing so, we intend to dispatch our foundation design technology to the world by a single voice. This code just has been established as one of JGS Standards under the name ‘Principles for Foundation Design Grounded on Performance Based Design Concept’.