Abstract: To investigate the degradation characteristics of caragana with different growth years in rumen of beef cattle, five experimental groups were set according to the growth years of caragana, which were experiment group 1（one-year-old）,experiment group 2（second-year-old）,experiment group 3（third-year-old）,experiment group 4（fourth-year-old） and experiment group 5（10-year-old）.The whole plant samples in each group were cut into 1 cm stem segments, crushed and sieved, and then put into self-made nylon bags. Each group had three parallel samples and each group had seven nylon bags. The nylon bags were rinsed and dried at the 6, 12, 18, 24, 36, 48, 72 hours after feeding, respectively.The conventional nutrients（dry matterDM,crude proteinCP,crude fat EE, neutral detergent fibreNDF acid detergent fibreADF,and crude ashAsh）were determined after grinding and sifting, and the relevant indexes such as real-time degradation rate and effective degradation rate were calculated.The results showed that the contents of DM（55.11%）, NDF（69.88%）, ADF（59.55%）, and Ash（6.51%） in experiment group 5 were all the highest; the CP content（15.36%） was the highest in experiment group 1, and the EE content（4.22%） was the highest in experiment group 2; there were no significant differences in the contents of CP、EE、NDF and ADF between the experiment group 1 and the experiment group 2 with the extension of caragana growth years（P＞0.05）,while only CP content in the experiment group 3 was significantly lower than that in the experiment group 1（P＜0.01）.With the extension of rumen degradation time, the rumen degradation rates of DM, CP, NDF and ADF in each group gradually increased, and reached the maximum at 72 hours. The rumen degradation rates of DM and CP were the best in the experiment group 2,which were 68.10% and 75.84%, respectively.The rumen degradation rates of NDF and ADF were the best in the experiment group 1, which were 59.85% and 50.79%, respectively.The results indicated that under the conditions of this experiment, there was little difference in the nutritional content of caragana in the growth period of 1-3 years, but 1 year of caragana was not conducive to the ecological restoration of caragana forest, and 2-year-old caragana had better conventional nutritional component and rumen degradation characteristics, so 2-year-old caragana is the most suitable growth years for feeding herbivorous livestock.