The paper reports the new discovery of the late Triassic blueschists and glaucophanes and its geological significance in Caiduo Caka, Shuanghu area, central Qiangtang, northern Tibet, China. Based on the field survey and measurement of the studied tectonic mélanges geological section in the Caiduo Caka, Shuanghu region, we found that the middle-high pressure metamorphic rocks (glaucophanes-bearing blueschists) were developed in the grey-green metamorphic basic volcanic rocks(green schist) in the sixth bed of this section. The petrology of the blueschists, and the mineralogy and petrochemistry of the glaucophanes have been in detail researched. The results of 40Ar/39Ar isotopic dating of the glaucophanes minerals derived from the blueschists show that plateau age is 209±4Ma, and isochronal age is 216±4Ma. The plateau age and isochronal age of the glaucophanes are nearly the same, belonging to Norian stage of the late Triassic. The ages are in accord with regional middle-high pressure metamorphic rocks geological data of the Gangmar- Hongjishang-Shuanghu blueschists belts in central Qiangtang. Because of the particular tectonic settings and geological significance of glaucophanes and blueschists occurrence, therefore the discovery of the Caiduo Caka blueschists in eastern Shuanghu area and the 40Ar/39Ar isotopic chronological research have provided new important data to the Shuanghu tectonic mélange composition and the glaucophanes isotopic chronology, and to prove the key geological problem about the “eastward extension of the Longmucuo-Shuanghu tectonic mélange zone in central Qiangtang”. It seems possible that the middle-high pressure blueschist metamorphic rocks zone that extended discontinuously over 600km from Gangmacuo-Hongjishan- Rongma-Gaercuo, sequentially eastward to Caidaocaka in central Qiangtang northern Tibet, being bound up with late Triassic deep subduction orogenesis of the Longmucuo-Shuanghu tectonic mélange zone.