Methods for selectively assaying a target adiponectin multimer in a biological sample. Such methods accurately evaluate the relationship between a disease and adiponectin through selective assay of adiponectin multimers and provide information that cannot be obtained through measurement of the total amount of adiponectin alone. A method for selectively assaying of a target adiponectin multimer in a biological sample comprising distinguishing target adiponectin multimer from the other adiponectin multimers by using a protease and/or an antibody.