Provided is a spunbonded nonwoven fabric, including a fiber formed of a composition containing: a propylene homopolymer having a melting point of 140 C. or higher; a polyethylene; and at least one polymer selected from the group consisting of a polymer shown in (I), and a polymer shown in (II), in which the fiber has a sea-island structure, and an average length of an island phase is from 1 m to 500 m in a cross section taken along a major axis direction of the fiber, and a method for producing thereof, and in which the polymer shown in (I) is a random copolymer of a propylene with -olefin having specified number of carbon atoms and the polymer shown in (II) is a propylene homopolymer having a melting point of less than 120 C. satisfying the specified properties.