A macroscopic theory for cellular states with steady-growth is presented, based on consistency between cellular growth and molecular replication, as well as robustness of phenotypes against perturbations. Adaptive changes in high-dimensional phenotypes are shown to be restricted within a low-dimensional slow manifold, from which a macroscopic law for cellular-states is derived, as is confirmed by adaptation experiments of bacteria under stress. Next, the theory is extended to phenotypic evolution, leading to proportionality between phenotypic responses against genetic evolution and by environmental adaptation.  Evolutionary relevance of slow modes in controlling high-dimensional phenotypes is discussed. Last, if I have time, transition from exponential-growth to stationary phases is investigated as the breakdown of steady-growth.  A general law between the starvation time and lag-time to recover the cellular growth is discussed.