The present invention provides a method of suppressing the formation of a soluble association of an antibody in a solution； a method of suppressing the formation of a chemically degraded product of an antibody in a solution； and a method of stabilizing an antibody in a solution. The present invention also provides a solution-type antibody preparation in which the formation of a soluble association is suppressed； a solution-type antibody preparation in which the formation of a chemically degraded product is suppressed； a solution-type antibody preparation in which the formation of a soluble association, the formation of a chemically degraded product and the formation of an insoluble aggregate are suppressed； an agent for suppressing the formation of a soluble association of an antibody； an agent for suppressing the formation of a chemically degraded product of an antibody； and a stabilizing agent for an antibody.
