Abstract: Lop Nor is a desert area in the eastern part of the Taklimakan Desert in Xinjiang,China.It is extremely arid and there are scarcely any plants in this region.In 2013,Xinjiang Institute of Ecology and Geography,the Chinese Academy of Sciences,established a 1.3 hm².artificial ecological demonstration zone and introduced more than 70 plant species.Because of the extremely harsh natural conditions,fewer than 30 species have been introduced so far.In the process of growth and development,plants will be subject to a variety of abiotic factors.Water and temperature are the main factors affecting plant growth.Under the conditions of high temperature and water shortage,the plants adjust their physiological and biochemical processes to adapt the changes of temperature and moisture.In addition,the plants form a certain high temperature resistance and drought resistance mechanism.In order to study the drought resistance and high temperature resistance capability of different species,the high resistance species groups suitable for the severe environment and ensure the introduction of artificial vegetation to Lop Nor,the correlation,principal component and cluster methods were used to analyze the physiological and biochemistry indicators of 20 main introduced plant species in the artificial ecological demonstration garden in the Lop Nur area.The results are as follows: ① There was an extremely significant correlation between photosynthetic pigment and free proline content in leaves,both of them were at a high level under normal irrigation system; ② The indexes of plants were measured by four principal components,they were the photosynthetic capacity,enzyme activity of plant leaves,drought tolerance and organic solvent content in plant leaves.The principal component factor score and ranking showed that Elaeagnus angustifolia L.,Atriplex patens Iljin.and Sphaerophysa salsula DC.were the top 3,which revealed that the growth status of the three species was the best; ③ When the Euclidean distance was 7,the plants were divided into four categories by cluster analysis: (Ⅰ) General growth plants,including Apocynum venetum L.,Calligonum mongolicum Turcz.and other plants,accounting for 80% of the total samples,the high sugar content in leaves of these plants was the main physiological characteristic; (Ⅱ) Good growth plant,Lycium barabrum L.,the high photosynthetic pigment content high soluble protein and high free proline content in leaves were the main physiological characteristics; (Ⅲ) Dominant plants,Atriplex patens Iljin.and Sphaerophysa salsula DC.,the high photosynthetic pigment content but the low soluble sugar and free proline content in leaves of these plants were the main physiological characteristics; (Ⅳ) Best growth plant,Elaeagnus angustifolia L.,the extremely high Chla/b value in leaves but low one in other organic solvents were the main physiological characteristics .The results also showed that the physiological mechanism of introduced plants in the severe environment varied greatly.How do these dominant plants adapt the severe environmental conditions in their morphology and organization structure? How does the physiology of the plant change in such severe environment? What are the most significant factors for environmental stress change? What are the causes of this difference in the climate mechanisms of different plants adapting to drought? These issues should be carefully analyzed for future study.

Key words: introduced plants, plant physiology, principal component analysis, cluster analysis, severe habitat, Lop Nor