The present invention relates to a composition for treating osteoarthritis and a method for preparing the same, and more specifically, relates to a composition comprising hydrophilized sulfasalazine as an active ingredient and hyaluronic acid so as to enable effective treatment of osteoarthritis such as degenerative osteoarthritis by preventing joint wear in addition to symptom relief through intraarticular or local administration, and a method for preparing the same. When such a composition for osteoarthritis treatment is prepared by the preparation method according to the present invention, the dissolved state is maintained beyond a neutralization step after dissolution, preventing precipitation of sulfalazine by salting out occurring after neutralization , and thus a composition comprising high concentration of sulfasalazine can be prepared, and the composition prepared accordingly is highly effective in treating osteoarthritis, particularly degenerative osteoarthritis, through the intraarticular or local administration, since it comprises high concentration of sulfasalazine which had to be formulated at low concentration by conventional method due to poor solubility.
