Provided is a highly versatile polymerizable composition that allows the fabrication equipment to be washed easily with water, allows the fabricated object to be removed easily from the support, and allows easy curing by application of light rays of 400 nm or higher, in optical 3D fabrication by lamination fabrication. A photopolymerizable composition for stereolithography containing a water-soluble radical polymerizable compound (A) represented by formula (1), a photopolymerization initiator (B) that generates radicals upon application of light rays of a wavelength of 400 nm or higher, and an ionic surfactant (C). In formula (1), R1 is an organic group of valence a, a is an integer of 2 or higher, and R2 is hydrogen or an alkyl having 1-6 carbon atoms.