Photoresist monomers, photoresist polymers prepared therefrom, and photoresist compositions using the polymer are disclosed. The photoresist polymers include photoresist monomers containing fluorine-substituted benzylcarboxylate group represented by Formula 1. The photoresist composition has excellent etching resistance, heat resistance and adhesiveness, and is developable in aqueous tetramethylammonium hydroxide (TMAH) solution. As the composition has low light absorbance at 193 nm and 157 nm wavelength, it is suitable for a process using ultraviolet light source such as VUV (157 nm). In the Formula, R1, R2, R3 and m are defined in the specification.