To observe the therapeutic effect and mechanism of phenylethanoid glycosides from cistanche (PhGCs) on chronic mountain sickness (CMS) model rats,the red blood corpuscle,hemoglobin,hematocrit value,endothelin-1 (ET-1),and nitric oxide (NO) content,nitric oxide synthase (NOS) enzyme activity,the expression and mRNA levels of peroxisome proliferator-activated receptor alpha(PPAR-α),hypoxia-inducible factor 1(HIF-1α),vascular endothelial growth factor (VEGF) in the homogenate of lung tissue were measured.Results showed that PhGCs and Rhodiola rosea can reduce the right ventricular hypertrophy and the ET-1 content,increase the NO content and the enzyme activity of total nitric oxide synthase (T-NOS),endothelial nitric oxide synthase (eNOS),inducible nitric oxide synthase (iNOS),down-regulate the expression and mRNA levels of HIF-1α and VEGF,up-regulate the expression of PPAR-α in the homogenate of lung tissue of CMS;furthermore,the red blood corpuscle,hemoglobin and hematocrit value had no significant changes compared with rats in model group.In this study,it was confirmed that PhGCs inhibit HIF pathways and activate NO pathways.