Abstract: AIM　To analyze the phenylethanoid glycosides in Cistanche deserticola Y.D.Ma and its alternatives. METHODS　An HPLC/MS/MS method has been developed for the analysis of seven kinds of phenylethanoid glycosides in Cistanche deserticola Y.D.Ma, C.salsa (C.A.Mey) G.Beck and C.tubulosa (Schenk) R.Wight. The ［M-H］- ions were observed for five standards and Cistanche extracts. The glycosidic linkages, the core, and the attached sugar (s) of the phenylethanoid glycosides can be determined from the collision-induced dissociation spectra of the molecular. RESULTS　Seven kinds of phenylethanoid glycosides (echinacoside, acteoside, cisacteoside, isoacteoside, 2′-acetylacteoside, cistanoside A, osmanthuside B) in Cistanche deserticola Y.D.Ma, six kinds (echinacoside, acteoside, cisacteoside, isoacteoside, 2′-acetylacteoside and cistanoside A) in C.salsa (C.A.Mey) G.Beck and five kinds (echinacoside, acteoside, cisacteoside, isoacteoside and 2′-acetylacteoside) in C.tubulosa (Schenk) R.Wight were detected. CONCLUSION　The difference of the relative distribution of these phenylethanoid glycosides in each extract was found out. Phenylethanoid glycosides are the specific constituents in Cistanchis, which can be used to distinguish different species in Genus Cistanchis.