The present invention has an object to provide an antibacterial aqueous pharmaceutical composition and an aqueous pharmaceutical composition which have a sufficiently low gelation temperature even when new quinolone antibacterial agents such as ofloxacin as the active ingredient and can be retained at the administration site for a long time by virtue of rapid viscosity increase after administration in spite of their being liquid at administration and thereby attain high availability of pharmaceutical agent.The present invention relates to an antibacterial aqueous pharmaceutical composition which comprises: 2.8 to 4 w/v % of methylcellulose, the 2 w/v % aqueous solution of which has a viscosity of 12 mPa·s or below at 20° C.; 1.5 to 2.3 w/v % of citric acid; 2 to 4 w/v % of polyethylene glycol; and 0.1 to 0.5 w/v % of ofloxacin.