To obtain a conjugate fiber composed of a high-melting resin component such as a crystalline polypropylene, etc., and a polyethylene-based low- melting resin component, having a section of a modified structure forming specific connected parts, a low heat treatment temperature in a nonwoven fabric formation process and excellent opacifying properties, useful for a nonwoven fabric and an absorbing article.

This fiber comprises (A) a component A 1 of at least one high- melting resin selected from a crystalline polypropylene and a propylene-based copolymer [preferably a copolymer resin of 85-99 wt.% of propylene and 1-15 wt.% of ethylene or a terpolymer resin of 84-98 wt.% of propylene, 1-10 wt.% of ethylene and 1-15 wt.% of butene-1] and (B) a component B 2 composed of a polyethylene-based resin having a melting point lower than that of the component A and 0.910-9.70 g/cm3 density, has a section of a modified structure in which the component A makes a strand radiately extend from the central part outward to form branched parts and the component B 2 is bonded to the branched parts of the component A to form connected parts.