| Buckwheat can be served as edibles and medicaments which has rich nutritional value. It has been recognized as important resources of development modern functional food. It has the strong competitive power in the domestic and foreign markets, especially after our country joined WTO, large quantities of grains'trend drops in the foreign market, but the buckwheat and the miscellaneous grains market have the strong tendency. At present, consideration of some chemistry anti-oxidant additives cost, thus seeking the new highly effective and low poisonous natural food oxidation inhibitor becomes the hot spot of research. Buckwheat is one of most important plants in China and even the world. The anti-oxidant activity material develops from the buckwheat and the derivative, not only originates widely, low cost, high security, and consumer accept easily. However, because buckwheat research had a late start, its basic reseach has been very week, the effective component research is not deep, especially in some specific effective component's pharmacological action research is also quite rare, it has become an urgent problem that need being solved in the buckwheat modernization process. Therefore it have the vital significance of carring on the buckwheat anti-oxidan activity development research.In this paper, phenol compound were extracted from the buckwheat by employing microwave method. The total phenolics and total flavonoids contents, total antioxidant capacities along with ?HO, DPPH?,O2-? radical scavenging ability of buckwheat ethanol extracts were examined. The results showed that:(1) The result indicated that there was great difference in total phenolics and total flavonoids contents, total antioxidant capacities (FRAP value) of ethanol extracts of tartary and common buckwheat seeds, but not remarkable difference in different cultivars of the same type. All of the buckwheat seeds were participated in the national buckwheat variety regional test. Total phenolics contents and total antioxidant capacities (FRAP value) of tartary buckwheat flour was approximately two~three times higher than that of commom buckwheat flour. In contrast, total phenolics and total flavonoids contents, total antioxidant capacities (FRAP value) of commom buckwheat hull was higher than that of tartary buckwheat hull and the differences was significant.(2) Anti-oxidant activity of five kings of buckwheat flour were determined. The result showed that: Total phenolics and total flavonoids contents of tartary buckwheat flour was approximately two times higher than that of commom buckwheat flour and Xinong 9909 was highest, respectively, for 268.73±5.03mg/g, 59.57±9.56mg/g. Total antioxidant capacities (FRAP value) of tartary buckwheat flour was approximately three times higher than that of commom buckwheat flour and Jiujiang tartary buckwheat was highest (2.54±0.38 mmol/100g). Xinong 9909 has the higehest rate of DPPH·radical,Hydroxyl radical and Superoxide anion scavenging ability in the five kinds of buckwheat flour ethanol extracts, and IC50 value were 43.25mg/L, 0.24mg/ml, 0.12mg/ml respectively.(3) Anti-oxidant activity of five kings of buckwheat hull were determined. The result showed that: Total phenolics and total flavonoids contents of commom buckwheat hull was higher than that of tartary buckwheat hull and Yuqiao-4 was highest, respectively, for 336.73±12.03mg/g, 121.30±2.73mg/g. Total antioxidant capacities (FRAP value) of Yuqiao-4 was highest (2.54±0.38 mmol/100g). Yuqiao-4 has the higehest rate of DPPH·radical and Hydroxyl radical ability in the five kinds of buckwheat hull ethanol extracts, and IC50 value were 13.97mg/L, 0.38mg/ml respectively. Xinong 9976 has the highest rate of Superoxide anion scavenging ability and IC50 value was 0.13mg/ml.(4) Anti-oxidant activity of five kings of buckwheat seedling were determined. The result showed that: Total phenolics content of tartary buckwheat seedling was approximately two times higher than that of commom buckwheat seedling and Xinong 9909 was highest (322.26±3.79mg). Total flavonoids content of Jiujiang tartary buckwheat was highest (60.77±5.22mg). Total antioxidant capacities (FRAP value) of tartary buckwheat seedling was approximately three times higher than that of commom buckwheat flour and Xinong 9920 was highest (6.82±0.08 mmol/100g). Xinong 9920 has the higehest rate of DPPH·radical and IC50 value was 3.23mg/l. Jiujiang tartary buckwheat has the highest rate of Hydroxyl radical and Superoxide anion scavenging ability in the five kinds of buckwheat seedling ethanol extracts, and IC50 value were 88.31mg/L, 13.16mg/L respectively.(5) Cultivation area was an influential factor to the phenolic compounds content and anti-oxidant activity. Phenolic compounds contents and anti-oxidant activity of the whole plants above the ground of buckwheat cultivated in different ecological environments were determined. The results showed that the total phenolics and flavonoids content, anti-oxidant activity rose and then declined with the exception of that of plants cultivated in Zhangbei of Hebei which was highest in the seedling stage and declined gradually in the remaining growing stage. Total phenolics and flavonoids contents, anti-oxidant activity of tartary buckwheat was higher than that of commom buckwheat , and in the decreasing order: Xinong 9920>Jiujiang tartary buckwheat>Pingqiao 2>Yuqiao 2.
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