Provided are a method for preparing a highly active human mesenchymal stem cell, which includes forming a spherical cell aggregate by cultivating human mesenchymal stem cells against gravity； a highly active stem cell prepared thereby； a cell therapeutic agent including the stem cell aggregate； and a method for forming a spherical cell aggregate by cultivating human mesenchymal stem cells, wherein the amount of E-cadherin in the mesenchymal stem cell is increased during the cultivation.
