Abstract: The anatomical structures of leaves of 3 species i.e. Saussurea medusa Maxim, Saussurea gnaphalodes (Royle)Sch, Saussurea paxiana Diels. in Saussurea grown in Qilianshan(halt≈5 000 m) were comparatively studied with the method of paraffin section. The obvious features of 3 plant species are as follows: the cell of upper epidermis in lamna is in one layer and cuticle is thick. The leaves have their stoma in both leaf surfaces and stomata that are not sunken. Epidermal hairs are 1 cell wide. The three plant species are all bifacial leaf. Palisade mesophyll which is made up by 2~3 layers is well developed, but there is quitle large intercellular spaces among palisade mesophyll and among spongy mesophyll. Aerenchyma is well developed in mesophyll. The three plant species all have anomaly schizogenous intercellular cavity. There is a little idioblasts in the phloem. All these contribut to the results of long-term effects of harsh environment on Qilianshan. There are obvious differences among them such as the color of leaves, the cell characteristic of palisade mesophyll, the development of vascular bundle, the structure of secretory canal, schizogenous irregular cavity, etc.

Key words: Qilianshan, Saussurea, leaves, anatomical structures