PROBLEM TO BE SOLVED: To provide a polymer composition which can fix the formed hair style by forming the hair at the hair temperature of 50°C or higher and subsequently cooling the hair temperature to a level lower than 50°C, and has an excellent set-keeping ability and to provide a cosmetic composition containing the same.SOLUTION: The polymer composition contains the following polymer A and polymer B. The content of an organopolysiloxane segment to the total of the polymer A and the polymer B is 30 mass% or more and 70 mass% or less. Polymer A is an organopolysiloxane graft polymer which has an organopolysiloxane segment as a principal chain, and has a polymer segment derived from an unsaturated monomer as a side chain, wherein the content of the organopolysiloxane segment in the organopolysiloxane graft polymer is more than 70 mass% and 90 mass% or less. Polymer B is a polymer containing 90 mass% or more of repeating units derived from an unsaturated monomer same as the unsaturated monomer which constructs the side chain of the polymer A.
