A latex reagent for analyzing adiponectin, comprising a suspension of latex particles carrying a substance which specifically binds to adiponectin, is disclosed. Further, a method for analyzing adiponectin, comprising (1) obtaining a biological liquid possibly containing adiponectin, and (2) bringing the biological liquid, while maintaining the state in which the biological liquid is obtained, into contact with a suspension of latex particles carrying a substance which specifically binds to adiponectin, and optically analyzing a degree of latex-particles-agglutination, is disclosed. According to the latex reagent and the method for analyzing adiponectin, a predilution or pretreatment of the biological liquid to be analyzed is not necessary. Further, the analysis can be performed rapidly and conveniently, and facilities therefor are not limited.