Abstract: 【Objective】 The research is to study the nitrogen metabolism in Cabernet Sauvignon during the period of dormancy. 【Method】Taking Cabernet Sauvignon as experimental materials, this research was conducted to investigate the variation of nitrogenous compounds and relative enzymatic activity in the buds, phloem and xylem of one-year-old cane, and roots during the period of dormancy induction and release in Yangling region. Measure the indexes of the nitrides, total nitrogen, total protein, soluble protein content, nitrogen metabolism-related enzyme activity, nitrate reductase activity, protease activity were determined, and the proteins in various grape organs at dormant phase were analyzed by using SDS-polyacrylamide gel electrophoresis.【Result】The contents of total nitrogen , protein and soluble protein in different parts of grape from high to low were buds＞roots＞phloem＞xylem，especially total nitrogen and protein in buds increased obviously. Contents of soluble proteins decreased gradually during the dormant induction, and increased gradually during the dormant release. Nitrate reductase activity of different dormant organs or tissues from high to low were buds＞roots＞phloem＞xylem. From dormancy to germinating stage, nitrate reductase（NR）activity generally decreased. In different organs of grapevine, glutamine synzyme activity in buds was maximal, during the period of deep dormancy, the glutamine synzyme activity was lowered to a minimum, the general trend of glutamine synzyme activity in buds was rising with two peaks during the dormant period. In the early dormancy, protease activity decreased with the deepening of sleep, and increased with the lifting of dormancy and germination (except buds). A large number of proteins emerged in the period of grape dormancy.【Conclusion】The buds, one-year old canes phloem, xylem and nitrogen compounds content, type and enzyme activity of the root changed before and after dormancy in the natural process of dormancy and germination.