Providing a disinfecting solution for a nonionic soft contact lens, which solution contains polylysine as a disinfectant, and which is composed without using auxiliary disinfectants and tonicity agents that cause deterioration of a disinfecting effect of polylysine, so as to advantageously maintain the disinfecting effect of polylysine, and to have an improved compatibility with respect to the nonionic soft contact lens. The disinfecting solution 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 250-330mOsm/kg and an electric conductivity of 130-750mS/m.
