A disinfecting solution for a nonionic soft contact lens, which solution contains polylysine as a disinfectant, and further contains: 0.1-1.0% by weight of a component (A) which is an acidic tonicity agent having at least one carboxyl group; 0.10-1.25% by weight of a component (B) which is a basic tonicity agent having an amino group; and 0.1-2.0% by weight of a component (C) which is at least one of a nonionic tonicity agent and an amphoteric tonicity agent, wherein each of the components (A) to (C) has a molecular weight of not larger than 200, and a ratio of a molar concentration of the component (A) to a molar concentration of the component (B) is not larger than 1.2. The disinfecting solution has a pH of 6.5-8.0, an osmotic pressure of 250-330 mOsm/kg and an electric conductivity of 130-750 mS/m.