This paper shows the problems on classification of seed quality based on 《Classification of forest tree seed quality》(GB 7908-1999). For example, to Pinus yunnanensis ,seed quality with 76% germination is considered as the first grade and seed quality with 74% germination is for the second grade. In fact, there are no marked differences between 76% and 74%. It also shows the method to solve that problem by statistical hypothesis test. At the same time, it points out that seed quality classification is not able to indicate real seed quality well according to GB 7908-1999.