The present invention provides a positive-tone photosensitivity resin composition comprising (A) an alkali-soluble acrylic resin, the alkali-soluble acrylic resin containing at least one structure unit selected from the group consisting of the following structure unit (1), structure unit (2), and structure unit (3), wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R, U, V, X, Y and Z are defined the same as the specification; (B) a naphthoquinone-diazide group containing compound; and (C) an solvent, the solvent is selected from the group consisting of ethers, ketones, esters, aromatic hydrocarbons and acetoacetates.