This invention relates to a method to producing a spheroid cell population of adult stem cells, comprising culturing adult stem cells on a thin film made by biocompatibility polymer materials. The film can be covered on the surface of other basic material through a chemical or physical method. The biocompatibility polymer material is chitosan, alginate, hyaluronic acid, tremella polysaccharide, polycaprolactone or any combination thereof. The adult stem cells cultivated by the method are spherical in shape and have outstanding self-renew and stemness maintenance capability. The method can be used for sieving and purifying stem cells having better self-renew capability and can be used for preparing medical compositions. The adult stem cells cultivated by the method achieves excellent effects on nano partical ingesting efficiency and gene transfer efficiency.