Ginkgo biloba L. a dioecious, precious relict plant which contains rich flavonoids, terpene lactone and polyprenols with important biological activities producing from secondary metabolites, originated from China, has been known as living fossil with important value of research and utilization. The content of flavonoid compounds is an important quality indicator for national standard of Grades of seed stone quality for ginkgo and seed stone, extraction of Ginkgo biloba EGb productions in the international...