The present invention provides adiponectin expression-inducing agents, and therapeutic agents using the same for obesity and obesity-related diseases such as cardiovascular diseases or metabolic diseases, as well as methods of searching for adiponectin expression-inducing agents. KLF9, which can bind to the 32-bp fragment of position −188 to position −157 from the adiponectin expression start site, was demonstrated to enhance adiponectin promoter activity. Therefore, the present invention uses KLF9 as an adiponectin expression-inducing agent, and suggests that KLF9 replenishment therapy is useful for preventing and/or treating obesity or obesity-related diseases including metabolic diseases such as insulin resistance and type II diabetes, and cardiovascular diseases.