The present invention provides a crosslinked hyaluronic acid composition containing self-crosslinking hyaluronic particles with an equilibrium swelling ratio of 3-10 times and an aqueous solvent, wherein the dry weight of the self-crosslinking hyaluronic particles is 3-8 w/v% of the total volume of the crosslinked hyaluronic acid composition. By using self-crosslinking hyaluronic particles with an equilibrium swelling ratio within said prescribed range in the crosslinked hyaluronic acid composition of the present invention, viscosity does not increase rapidly even at high concentrations so sufficient therapeutic effects on osteoarthritis of the knee even at infrequent doses can be obtained when the crosslinked hyaluronic acid composition is used as an injection solution.