Abstract: To investigate the effects of exogenous gibberellin（GA₃） on Paulownia seed germination and seedling physiological characteristics under NaCl stress, the seeds of Paulownia tomentosa,Paulownia kawakamii and Paulownia fortunei were soaked in different concentrations of GA₃ solution for 12 h, and the germination-related parameters and antioxidant enzyme activities of these treated Paulownia seeds were studied under 0.3% NaCl stress.Also, the content change of malondialdehyde（MDA）,proline（Pro） and chlorophyll（Chl） were also determined.The results showed that NaCl stress significantly inhibited the germination and seedling growth of Paulownia seeds, and seed-soaking treatment with appropriate concentration of GA₃ increased the germination rate, germination potential, germination index and vigor index of Paulownia seeds under NaCl stress.Meanwhile, this treatment promoted the growth of Paulownia root and bud, enhanced the activity of superoxide dismutase（SOD）,peroxidase（POD） and peroxidase（CAT） in seedlings under NaCl stress, and decreased the content of MDA.It increased the contents of Pro and Chl, and significantly alleviated the inhibition of NaCl stress on the growth of Paulownia seeds and seedlings.Additionally, there were differences among different varieties, and the optimum concentrations of GA₃ for alleviating effect to salt stress in P. tomentosa, P. kawakamii and P. fortunei were 400 mg·L^-1,600 mg·L^-1 and 600 mg·L^-1 respectively.