A method for preparing for glycoprotein in Chinese yam to enhance the activity of metabolic enzymes of brain mitochondria may include steps of: grinding the Chinese yam into fine powers adding water into the fine powers and heating up to 50-100°C to form a mixture, and the amount of water is 2 to 5 times as much as the Chinese yam extracting the mixture twice, and combining the two extracting solutions concentrating the extracting solution and adding 95% ethyl alcohol to obtain a first mixed liquid with 60-75% ethyl alcohol concentration and white sediments start to appear separating the white sediments from a first supernate adding 95-98% ethyl alcohol in the first supernate to obtain a second mixed liquid with 90-95% ethyl alcohol concentration and brown emplastic sediments start to appear removing a second supernate and collecting and drying the brown sediments to obtain brown glycoprotein in Chinese yam.
