The present invention relates to a use of bamboo or bamboo extract to prevent or treat symptoms related to decrease of androgen; a composition for androgen agonist comprising bamboo or bamboo extract; a method for preventing or treating symptoms related to decrease of androgen by administering composition for androgen agonist; and a method of preparing composition for androgen agonist. The present composition obtained from natural material can be used as Phyto-androgen for the preventing and treating symptoms of male climacteric without dangerousness according to hormone replacement therapy.