A photosensitive composition and a photoresist are provided. The photoresist is formed by compounding a photosensitive composition. The photosensitive composition includes a binder agent, a first photomonomer, and a photo initiator. The first photomonomer has at least a lactic oligomer and at least two unsaturated acrylic functional groups, wherein the first photomonomer has an amount of about 25-95 parts by weight relative to 100 parts by weight of a solid content of the binder agent. The photoinitiator has an amount of about 0.5-15 parts by weight relative to 100 parts by weight of the solid content of the binder agent.