The dynamic changes of proteins, amino acid and activities of nitrogen metabolism enzymes in Ginkgo biloba seeds were studied during the different germination stages. The results indicated that the contents of proteins gradually declined during the germination. The amount of amino acid was very low in the endosperm of seeds without storage. During germination, its amount increased, however, it declined when radicle emerged and then it slowly increased with the sprout growth. Endopeptidase activity was found to increase during germination, its maximum reached to 0. 048 mg/(g ? h), then it gradually declined. The activity of peptidase maintained its initial levels at the early stages of germination, but increased slightly when radicle broke through seed capsules, and then increased. Nitrate reductase activity increased with the germination, and slowly declined when the emergent began to grow. The vegetative storage proteins (VSPs) in endosperm were supply of nitrogen fountain. During germination, VSPs were degraded and translated into other vegetative substances that were used to germinate and growth. The degradation of proteins was closed related to the activities of nitrogen metabolism enzymes.