NBFs, melt-adhesive bicomponent fibers manufactured by Daiwabo Co., Ltd., are sheath/core type composite composed of polyethylene/polypropylene or polyethylene/polyester. This paper describes on the background of development, the properties and the applications of a new type of NBFs. This fiber was found to provide the nonwoven fabrics having soft handle, high strength and wide thermal window in heat bonding process. It is applicable, therefore, to the coverstock of diaper, sanitary napkin and so on.