Provided by the present invention are an aptamer having an inhibitory activity on FGF2; a complex containing an aptamer having a binding activity or an inhibitory activity on FGF2, and a functional substance (e.g., affinity substance, labeling substance, enzyme, drug delivery vehicle, or drug and the like); a medicament, diagnostic reagent or labeling agent containing an aptamer having a binding activity or an inhibitory activity on FGF2, or a complex containing said aptamer and a functional substance; and the like.