Abstract: Early Response to Dehydration（ERD） gene is a kind of gene that can quickly respond to drought stress.In this study,the EuERD16 gene of Eucommia ulmoides was cloned,and its bioinformatics analysis was carried out.The expression of EuERD16 gene in different tissues and under stress conditions of Eucommia ulmoides was analyzed by real time quantitative PCR technology,and then the over expression vector was constructed.Overexpressed EuERD16 gene tobacco（Nicotiana tabacum） plants were obtained by Agrobacterium-mediated method,and the drought resistance function of EuERD16 gene in Nicotiana tabacum was analyzed.The results showed that the CDS sequence of the EuERD16 gene was 387 bp,encoding 128 amino acids,and had high homology with the AtERD16 sequence of Arabidopsis thaliana.Both of them were one ubiquitin monomer（76 amino acids） fused with one 60S ribosomal subunit L40（52 amino acids）,belonging to the ubiquitin extention protein subfamily.The promoter region of this gene contained response elements such as light,drought and low temperature.In Eucommia ulmoides seedlings,EuERD16 gene is highly expressed in stems and roots.In mature E.ulmoides trees,EuERD16 gene is highly expressed in male and female leaves in March and May,and female fruits in July,and is induced by signals of 20% PEG6000 to simulate drought,blue light and low temperature stress.Under drought stress,the wilting degree of EuERD16 transgenic tobacco was less than that of wild type tobacco,and the enzyme activities of CAT,SOD,POD and the content of proline were significantly higher than those of control group（P＜0.05）,while the contents of H₂O₂,O₂^- and MDA were significantly lower than those of control group（P＜0.05）.The result showed that EuERD16 participated in the drought stress response of E.ulmoides,providing a reference for further study on drought resistance mechanism of E.ulmoides.