It is intended to provide bactericidal solutions having a biological toxicity lowered as far as possible to thereby ensure a sufficient safety and, at the same time, exerting an excellent bactericidal effect or preserving effect. Bactericidal solutions containing at least one bactericide which contain an isotonic agent having an electrical conductivity of a 0.1 mol/L aqueous solution of 500 mS/m or less and in which the concentration of sodium chloride in the bactericidal solution is controlled to 0 to 0.2% by weight and the total concentration of phosphoric acid and its salt is controlled to 0 to 0.5% by weight.
