A photoresist developer composition is provided, to improve miscibility and to suppress or minimize the generation of residue after development, thereby enhancing the precision of photoresist pattern. The photoresist developer composition comprises 1-10 wt% of an inorganic alkali; 0.1-3.0 wt% of an organic solvent; 1.0-20.0 wt% of a surfactant; and 67-97.9 wt% of water. Preferably the inorganic alkali is selected from the group consisting of KOH, NaOH, sodium phosphate, sodium silicate, sodium carbonate, sodium bicarbonate and their mixtures; the organic solvent is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, butanol, diacetone alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropyl glycol monomethyl ether, dipropyl glycol monoethyl ether and their mixtures; and the surfactant is a mixture of a nonionic surfactant and an anionic surfactant.