The invention relates to a nanometer
microsphere or a nanometer hollow sphere of
casein or
casein-
polyacrylic acid compound, and a nanometer
microsphere or a nanometer hollow sphere of cross-linking
casein, wherein the nanometer
microsphere or the nanometer hollow sphere of the casein or casein-
polyacrylic acid compound consists of a compound of casein and
polyacrylic acid, and the average grain
diameter of the nanometer microsphere or the nanometer hollow sphere is 170-370nm; the nanometer microsphere or the nanometer hollow sphere of cross-linking casein consists of cross-linking casein, andthe average grain
diameter of the nanometer microsphere or the nanometer hollow sphere is 240-500nm. The nanometer microsphere or the nanometer hollow sphere of cross-linking casein has good
biocompatibility and biodegradability without causing
organism immunoreaction; degradation products of the nanometer microsphere or the nanometer hollow sphere of cross-linking casein can be absorbed and metabolized by a
human body and has the treatment action, nutritive efficiency and the like on the
human body, and therefore, the nanometer microsphere or the nanometer hollow sphere of cross-linking casein can be used as a carrier of drugs. The invention discloses a preparation method of the nanometer microsphere or the nanometer hollow sphere of the casein or casein-polyacrylic acid compound, and apreparation method of the nanometer microsphere or the nanometer hollow sphere of cross-linking casein.