An alkaline soluble resin, a process for preparing the same, and a photoresist composition containing the same. The alkaline soluble resin is a polyether chain-containing acrylate alkaline soluble resin. A photoresist composition comprising said alkaline soluble resin can reduce the slope angle of the film layer and prevent gaps which cause light leakage from forming in the junction between the colored film layer and the black matrix. Moreover, the coating and the rubbing effect of the orientation layer can be improved.