Abstract: This experiment was conducted to study the morphological adaptations of the superior cervical ganglion (SCG) of the yak to its habitat as well as investigate the adaptive mechanism of sympathetic nervous system to the QinghaiTibet plateau in plateau animals. The morphological characteristic of SCG of the yak was compared and analyzed with the cattle by morphometry method and SPSS16.0 software with HE and Toluidine Blue stained section. The results showed that: 1) The length, width and thickness of SCG of the yak were smaller than cattle significantly (P<0.01); 2) The SCG of yak were consisted with capsule, ganglion units, neuropil, vessel and connective tissue; Compared with cattle, yak has a thinner capsule and smaller proportion of connective tissue, while tissue in ganglion was more dense; 3) In both yak and cattle, the ganglion units was consisted with ganglion cell, satellite cell, fibroblasts, capillary and neuropil, while attractive characteristic was that the number of ganglion cells, satellite cells and neuropil in unit visual field of the ganglion units of the yak were similar to the cattle (P=1), but the number of the yak’s capillary were more than that of the cattle (P<0.01); 4) Similar to cattle, the head of SCG was mainly composed with ganglion units and tail was mainly nerve fibers in yak. These results indicated that as a yearround grazing and half wild animal, yak living in the QinghaiTibetan Plateau and its SCG have evolved with some morphological characteristics such as small volume, less ganglion cells and nerve fiber, and rich vessel and so on, that enabling them to adapt the ecotope well.