Abstract: The enzyme activities of PAL from six year old Ginkog biloba leaves in the potted orchard were induced by four groups of metal ions respectively The PAL activities and flavonoids content were measured using the UV--Vis spectrophotometer. Changes of the whole year were also studied. The results showed that four groups of metal ion treatments had significant effects on the PAL activities and flavonoids contents in Ginkgo leaves. The treatments with 0.1% and 0.3% FeSO4, 0.1%, 0.20//00 and 0.3%ZNSO4, 0.1%, 0.30/4o and 0.5% MnSO4, 0.1% and 0.4% CuSO4 not only enhanced flavonoids contents, but also extended the periods of best-collecting-leaf. The optimum combination was 0.1% FeSO4, 0.2% Zn-SO4, 0.3% MnSO4, 0.4% CuSO4. It could improve flavonoids content up to 1.6194%.