The integration of knowledge from many disciplines and vast amount of biological data in the post-genome era together with mathematical and information sciences is moving the world towards a new generation of life science where physiological and pathological information from the living human body can be quantitatively described in silico across multiple scales of time and size and through diverse hierarchies of organization. The Physiome Project represents such emerging sciences. The challenge is to understand and quantitatively integrate not only structure and function of biological entities such as ion channel proteins and enzymes on a single spatio-temporal scale, but also functional relationships between entities across multiple scales. This integrative approach is in stark contrast to the linear approach of reductionist life science, and it will allow us to understand the mechanisms underlying biological functions that will emerge through the dynamics of each element and large aggregations of the elements. In this talk, we will discuss several points of the challenge that are expected to be resolved through the Physiome Project. We also introduce several ongoing researches along our physiome project. For details, please visit http://www.physiome.jp and http://www.mei.osaka-u.ac.jp/gCOE/english/.