The changes in three endogenous hormones, phytohormones gibberrelicacid (GA3), indoles-3-acid (IAA) and abscisic acid (ABA), were studied aroundgermination and under tress of different density of Pb2+ between two species ofAmmopiptanathus. It was found that (1) around germination, in XinjiangAmmopiptanthus the rate IAA decreased 77.80%, and the rate of ABA decreased98.90%; and in Mongolia Ammopiptanthus the rate of IAA decreased 75.80%, the rateof ABA decreased 66.20%, and the GA3 contents in both had no big change. (2) Withthe increase in Pb2+ concentration (20-1 500 mg?L-1), the IAA decreasedsignificantly; and only under the high density (more than 1 000 mg?L-1) of Pb2+,the GA3 was affected by it; the ABA did not change regularly. So the threeendogenous hormone levels of Mongolia Ammopiptanthus were higher than those ofXinjiang Ammopiptanthus.(3)the distributions of Pb2+ in Ammopiptanthus seedlingsare the root＞stems＞leaves. (4) the stress of high concentration of Pb2+ damagesirreversibly the leaf cells of Ammopiptanthus. This study can provide the basisof reference data for further research on the growth characteristics, resilienceand the mechanism of specific broad-leaved evergreen shrubs-Ammopiptanthus indesertification area.(XJEDU2004I08), 土壤学新疆自治区重点学科项目资助