Disclosed are a pharmaceutical composition for treatment of endometrium damage, a composition for enhancing implantation ability, and a pharmaceutical composition for prevention or treatment of infertility or subfertility. The pharmaceutical composition for treatment of endometrium damage includes decidual endometrial stromal cells and hyaluronic acid, the composition for enhancing implantation ability includes decidual endometrial stromal cells and hyaluronic acid, and the pharmaceutical composition for prevention or treatment of infertility or subfertility includes decidual endometrial stromal cells and hyaluronic acid.