Abstract: Under the background of global climate change,much attention has been paid to the study of the relationship between vegetation and climate,climate restricts the geographical distribution of vegetation and vegetation types reflect the climate characteristics. The plants adapt to climate,at the same time,have feedbacks to the climate. On the basis of field investigation and checking floras and the specimens preserved in herbaria,the detailed geographic distribution data (including the distribution map) and botanical data of Calligonum mongolicum; were provided here. Then the relation between its geographic distribution and climate factors was analyzed with Kira’s warmth index and coldness index,Xu’s humidity index,annual mean precipitation,annual mean sunshine hours,annual mean wind speed and other climate indexes. The results showed that ① In the distribution area of Calligonum mongolicum,its average annual biological temperature was 6-13 ℃,warm index was 41-143.8 ℃·mon,cold index was -31.2--53.9 ℃·mon,the extreme high temperature was 47.7 ℃and the extreme low temperature was -41.6 ℃,average annual temperature was 2.2-14.4 ℃,annual temperature range was 49.9 ℃,frost-free period was 80-225 d,sunshine time were 2 700-4 440 h,humid index was 0.1-5.2 mm·(℃·mon)^-1,potential evapotranspiration was 393.3-738.3 mm,average annual precipitation was 13.8-230 mm which had a bigger range,and its average annual wind speed was 1-4.8 m·s^-1. Besides,Calligonum mongolicum; was a plant growing in temperate or warm temperate,arid and semi-arid areas with high temperature,long sunshine time and high annual range; ② Principal component analysis showed that relative effect of climate factors on the distribution of Calligonum mongolicum were,temperate factor>low temperate factor>sunshine factor > wind speed factor.

Key words: Calligonum mongolicum, geographic distribution, climate, principal component analysis (PCA)