Abstract: The biological character of flowering were studied in 33 ancient male ginkgo trees which came from main distribution areas of Ginkgo Boliba L in China. The results showed that the flowering period of male ginkgo trees ranged from late March to middle April and flowering lasted for 3～7 days from south to north in 2006; the number of flower spikes on short shoot of 33 ancient male ginkgo trees ranged from 3.1 to 6.02 per shoot and the average number was 4.53 per shoot; the length of flower spikes ranged from 16.55mm to 32mm and the average number was 25.25mm; the width of flower spikes ranged from 5.2mm to 8.19mm and the average number was 6.83mm; the anther number of flower spikes ranged from 36.68 to73.26, and the average number was 50.31. Variance analysis indicated that 4 indexes among 33 ancient male ginkgo trees had significant difference.