Bicomponent fiber

A bicomponent fiber composed of a polyethylene-based resin (A) and a high-melting point resin (B) whose melting point is higher than that of the above polyethylene-based resin (A) by at least 10° C., the component ratio by weight of the polyethylene-based resin (A) to the high-melting point resin (B) being in the range of 50/50 to 10/90, and the polyethylene-based resin (A) forming at least part of the surface of the fiber longitudinally continuously wherein the polyethylene-based resin (A) is characterized by a Co-monomer Distribution Constant greater than about 45, a recrystallization temperature between 85° C. and 110° C., a tan delta value at 0.1 rad/sec from about 15 to 50, a complex viscosity at 0.1 rad/second of 1400 Pa·sec or less, a single differential scanning calorimetry (DSC) melting peak with the temperature range of 85° C. and 110° C., being an ethylene/propylene copolymer containing more than 50 Mol % of polymerized ethylene monomer, and being obtained through free radical polymerization in the presence of peroxide and chain transfer agents.