A propylene-based polymer comprising the following component (A) insoluble in p-xylene at 25° C. and component (B) soluble in p-xylene at 25° C., wherein (i) the weight average molecular weight (Mw) measured with GPC is 100,000 to 1,000,000, (ii) the content of the component insoluble in hot p-xylene is 0.3% by weight or lower, and (iii) the degree of strain hardening (λ max) in measurement of elongational viscosity is 2.0 or higher; and a method for producing the same, along with a resin composition comprising a propylene-ethylene copolymer (Z) in an amount of 50.0 to 99.9% by weight and a propylene-based polymer (M) in an amount of 0.1 to 50.0% by weight.Component (A): a component (CXIS) insoluble in p-xylene at 25° C., having requirements specified by (A1) to (A5). Component (B): a component (CXS) is soluble in p-xylene at 25° C., having requirements specified by (B1) to (B4).