AbstractStereoregularity and conformation of high polymers are reviewed in relation to symmetry. Stereoregularity of polypropylene is analyzed with two kinds of Bernoullian stochastic processes, while conformation of poly(vinylidene fluoride) in solution is related to that in the crystalline state. In both studies nuclear magnetic resonance spectroscopy is applied. A historical survey is also sketched for the relationship between the concept of symmetry and organic (including polymeric) molecules