An object of the present invention is to provide a novel propylene-based polymer capable of providing a propylene-based polymer with a good adhesion and coatability. The present invention lies in a propylene-based polymer having a propylene component with several characteristics including a weight-average molecular weight Mw from not smaller than 5,000 to less than 1,000,000 as measured by GPC, and Regio irregular units based on 2,1-inserted propylene monomer and/or 1,3-inserted propylene monomer present in its main chain and the sum of the ratio of regio irregular units based on 2,1-insertion and 1,3-insertion to all propylene insertions not smaller than 0.05%.