The present invention relates to a liquid preparation of a humanized antibody for treating an IL-6-related disease. The liquid preparation comprises 2-100 mg/mL of a recombinant humanized anti-human interleukin 6 receptor monoclonal antibody, 5-20 mM of a histidine salt buffer solution (or a buffer solution of a combination of 5-20 mM of a histidine salt and 5-20 mM of sodium acetate), 0.025-0.075% (volume ratio) of a surfactant, and 3-5% (mass-to-volume ratio) of a stabilizer and water for injection. The antibody preparation enhances the stability of the recombinant anti-human interleukin 6 receptor monoclonal antibody, prevents aggregation and degradation of the monoclonal antibody, and acid isomer increase. The preparation is applicable in stabilizing the structure and function of the humanized antibody.
