Abstract:Pb, Zn single stresses of 200 (P1, Z1), 400 (P2, Z2), 600 (P3, Z3), and 800 (P4, Z4) mg/kg and composite stresses of 100+100(M1), 200+200(M2), 300+300(M3), and 400+400(M4) mg/kg were set in this study using the potted seedlings of Magnolia officinalis subsp. biloba, and no Pb, Zn treatment as control(CK). A total of 13 treatments with different concentrations of Pb and Zn were designed to investigate the growth, physiological and lead and zinc accumulation characteristics of Pb and Zn seedlings after 90 d of treatment. The results showed that P1、P2、M2 treatments could increase the diameter, dry masses of above and below ground parts of Magnolia officinalis subsp. biloba seedlings. The contents of leaf photosynthetic pigments decreased to the lowest under P4 and Z4 treatments, and the contents of leaf photosynthetic pigments under combined stress were lower than that of CK. The activities of superoxide dismutase(SOD) and peroxidase(POD), soluble sugars, soluble proteins and free proline contents of leaves of Magnolia officinalis subsp. biloba. were higher than those of CK under all stress treatments. Compared with the control, the malondialdehyde contents of Pb and Zn stresses increased by 41.36%, 17.28% and 35.80%, respectively, with the concentrations of Pb and Zn were 800 mg/kg and the compound concentration was (400+400) mg/kg, and the plants were gradually damaged. With the increase of stress concentration, the Pb and Zn contents of both above-ground parts and roots of the plant gradually increased, but Pb and Zn mainly accumulated in the roots, and the Pb and Zn transport factors showed a decreasing trend. The analysis of all indicators showed that Pb and Zn stresses were highly tolerated by Magnolia officinalis subsp. biloba and had potential for remediation of Pb and Zn contaminated soil.