Hippophae is widely grown throughout the world. Pharmacopoeia of the People’s Republic of China recorded it had a good effect in promoting digestion, relieving cough, eliminating phlegm and improving circulation. As a subspecies of Hippophae rhamnoides, Hippophae rhamnoides L. subsp. turkestanica is exclusively distributed in Xinjiang in our country. Its Uygur medicine name is “Ji Han”. "Uygur medicine Zhi" recorded it had therapeutic value in the treatment of wetness-heat and blood diseases such as cough, stomach anorexia, nausea, vomiting, asthma, much sputum, difficulty in micturition, cirrhosis and hypertension. In recent years, global research and development of the Hippophae resources had made great progress, and a variety of Hippophae products were put on the market. However, the research reports about the Hippophae rhamnoides L. subsp. turkestanica, unique in Xinjiang were very few. What particular compounds are contained in the Hippophae rhamnoides L. subsp. turkestanica? Which kind of bioactive ingredients in the Hippophae rhamnoides L. subsp. turkestanica is more abundant than in other species? These questions were still unclear. The great majority of the Hippophae rhamnoides L. subsp. turkestanica products were confined to simple food processing. In this research, we carried out a systematic study on the chemical composition of Hippophae rhamnoides L. subsp. turkestanica fruits, optimized the extraction and purification process of its hepatoprotective fraction, and evaluated the hepatoprotective activity of the effective fraction. In the first chapter, species of the Hippophae genus and their distribution were introduced. Progress in studies of the Hippophae genus, including chemical composition, biological activity and products development were reviewed here. All of our research on the chemical composition of the Hippophae rhamnoides L. subsp. turkestanica is displayed in the second chapter. 21 compounds were separated and identificated from the n-BuOH and EtOAC fractions. In these compounds, 14 of them were obtained from the Hippophae rhamnoides L. subsp. turkestanica for the first time, and 6 of them were isolated from the Elaeagnaceae family for the first time. The total flavonoid aglycone contents of the Hippophae rhamnoides L. subsp. turkestanica were compared with other main species distributed in China, especially in Xinjiang province by HPLC. Hippophae rhamnoides L. subsp. turkestanica grown in Wushi of Xinjiang had the highest level, each gram of dried fruit containing 2.334 mg total flavonoid aglycone. Isorhamnetin is the highest concentrations flavonoid aglycone in all tested species of Hippophae. After the research on the middle and large polar chemical constituents, we continued to study on the lipid of the Hippophae rhamnoides L. subsp. turkestanica by GC-MS. At first, we compared the fatty acid and non-saponification lipid composition between the seeds and the peel of the Hippophae rhamnoides L. subsp. turkestanica fruits. More palmitoleic acid, squalene and vitamin E were in the peel oil, but more unsaturated fatty acids in the seeds oil. 41% of fatty acid in peel oil was palmitoleic acid, and 86% of fatty acid in seeds oil was unsaturated fatty acids. Then, we compared the fatty acid compostion of the Hippophae rhamnoides L. subsp. turkestanica with other main species which were distributed in China, especially in Xinjiang province. The Hippophae rhamnoides L. subsp. mongolica grown in Cele and the big fruit seabuckthorn distributed in Qinghe had the highest oil yield up to 28%. The Hippophae rhamnoides L. subsp. mongolica grown in Cele contained the most unsaturated fatty acids. 70.7% of fatty acid in it was unsaturated fatty acids. However, the Hippophae rhamnoides L. subsp. turkestanica contained highest level palmitoleic acid. 40.4% of fatty acid in it was palmitoleic acid. In chapter 3, the isolation and purification craft of the hepatoprotective fraction from Hippophae rhamnoides L. subsp. turkestanica was established, based on the chemical composition study in chapter 2 and the traditional Uighur medicine usage. Then, its hepatoprotective effect was evaluated by the model of carbon tetrachloride induced liver injury in rats. The optimal conditions for separation and purification was extract 5 times by 5 BV 50% ethanol in 90℃, 3 hours each time. Then, evaporated to dryness and diluted to 0.067 g crude drug / mL, adjusted pH to 6, chosed the AB-8 macroporous resin column. The flow rate of the sample solution is 2BV / h, and the sample solution volume was 9-10 BV. 70% ethanol was used to eluent, and the eluent volume was 3.5 BV. Each gram final product contained 0.49 OLE g total triterpenoids and 0.36 GAE g total phenolic. The hepatoprotective fraction had a strong ability of inhibition ABTS radical oxidation. It could inhibit the increase of AST, ALT, TG and TC in the blood of liver injurying rats inducting by carbon tetrachloride. Then, middle dose and high dose of the fraction could significantly reduce the necrosis and edema of the liver cells. Therefore, the Hippophae rhamnoides L. subsp. turkestanic hepatoprotective fraction have a potential price in the development of hepatoprotective new drugs and health products.