Abstract: This study is based on 20 complete skeletons of the Ochotona belonging to 2 species，one is Ochotona pallasi and another is Ochotona daurica．The vertebral columns，thoraces and the scapulas between the two species are remarkably different in many respects．Examination shows that:
1．The number of the thoracales in Ochotona pallasi is 16—18，but that in 0.daurica is always eighteen. Length of thoracales in the former is longer than that in the latter．2．Length of the cervicales in the O.pallasi is shorter than that of O.daurica．
3．There are 17 pairs of costae in the former ；while the latter have 16 pairs．4．In the former，width of the apeituia thoracis caudalis is two point five(2.5) times as much at length of the apeituia thoracis caudalis while in the latter,one point seven(1.7)．
5．Length of clavicula of O．pallasi is longer than that of 0 .daurica．

Key words: Ochotona paLLasi, Ochotona daurica, Skeletal morphology

摘要： 本文对比研究了20只蒙古鼠兔和草原鼠兔的骨骼标本，其结果如下：蒙古鼠兔(Ochotona pallasi)胸椎l6—l8块，草原鼠兔(Ochotona daurica)全是l8块。颈椎长度前者短于后者。蒙古鼠兔肋骨17对，草原鼠兔l6对，胸椎长度前者大于后者。前者的胸廊后口横径是背腹径的2.5倍，而后者仅1.7倍。前者锁骨长度大于后者。

关键词: 蒙古鼠兔、草原鼠兔、骨骼形态学