Amphiphilic molecules form self-assemblies (e.g. micelles, spherical or tubular vesicles) in water and these self- assemblies exhibit elastic response towards an external field, spontaneous movements coupled with chemical reactions, self-reproduction upon the addition of an amphiphilic precursor. If a self-replication of an informational molecule (e.g. DNA) proceeds in a self-reproducing vesicle, such a supramolecular system can be regarded as an artificial cell. A lipid world, in which abovementioned dynamics are occurring, serves a non-linear and open system that can be explored by modern molecular science.