The present invention provides a positive photosensitive resin composition which can form a cured film excellent in process resistance such as heat resistance, solvent resistance or long-time baking resistance and transparency, and which is excellent in photosensitive properties such as resolution and sensitivity, and which has high storage stability and a wide process margin. Further, the present invention provides a positive photosensitive resin composition having such high reliability that no deterioration of electrical characteristics will be led in its application for liquid crystal display devices. A positive photosensitive resin composition characterized by comprising an alkali-soluble resin which is a copolymer essentially comprising an unsaturated carboxylic acid derivative and an N-substituted maleimide and which has a number average molecular weight of from 2,000 to 20,000, a 1,2-quinone diazide compound represented by the formula (1): (wherein each of D independently is a hydrogen atom or an organic group having a 1,2-quinone diazide group, R.sub.1 is a tetravalent organic group, provided that at least one of D is an organic group having a 1,2-quinone diazide group), and from 5 to 50 parts by weight, per the alkali-soluble resin, of a crosslinking compound represented by the formula (2): (wherein n is an integer of from 2 to 10, m is an integer of from 0 to 4, and R.sub.2 is a n-valent organic group).