A photosensitive compound whose size is smaller than conventional polymer for photoresist, and which has well-defined (uniform) structure, and a photoresist composition including the same are disclosed. The photosensitive compound represented by the following formula 1. Also, the photoresist composition comprises 1 to 85 wt % (weight %) of the photosensitive compound; 0.05 to 15 weight parts of a photo-acid generator with respect to 100 weight parts of the photosensitive compound; and 200 to 5000 weight parts of an organic solvent. In the formula 1, x is 1, 2, 3, 4 or 5, y is 2, 3, 4, 5 or 6, and R and R′ are independently a chain type or a ring type of aliphatic or aromatic hydrocarbon group of 1 to 30 carbon atoms.