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The seasonal changes in nitrogenous compounds occurring during the natural senescence of gingko trees (Ginkgo beloba L) teat and bark tissue coincided with specific changes is the environment. Chlorophyll began to decrease from mid-August. The rate of decrease was gradual until early October, after which the rate sharply increased prior to the leaf abscission by early November. The fresh weight of leaf blade increased slightly until mid-September, thereafter decreased gradually. The dry weight of leaf blade, however, remained relatively constant except the slight decrease during the final stage of senescence. Nitrogen, protein, amino acids, and sugar began declining in leaf tissue when the daylength became less than 14 hours in the first week of August. By early November, leaf nitrogen and protein decreased 36 and 40%, respectively, from their respective highest values obtained in early August. on the other hand, the nitrogen and protein content of bark increased gradually from early August 1.43 fold comparing with the values of their minimum obtained in early August.
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