Provided are an alkali soluble binder resin that includes a monomer including an unsaturated double bond, an unsaturated double bond character monomer including a carboxylic acid and an unsaturated double bond character monomer including an allyl group as a repeating unit, in which a molecular weight distribution (Mw/Mn) is in a range of about 2.0 to about 3.5, and a negative-type photosensitive resin composition including the alkali soluble binder resin. Re-solubility, fine-patterned substrate adhesion and dispersion stability may be improved by including the alkali soluble binder resin according to the present invention.