Ecological risk was defined as the probability and possibly danger of the adverse ecological effects of the normal function in populations,the ecosystem and the entire landscape elements. It had a major significance for studying the spatial-temporal feature and influencing factors of wetland ecological risk,estimating the wetland risk areas to protect the ecological environment,to make a policy response on the process of the wetlands environmental management. This paper used ecological risk index (ERI) ,semi-variable function space analysis to study the spatial-temporal evolution of wetland ecological risk at the arid cold climates background in Bayanbulak world natural heritage site,Hejing County,Xinjiang. The data sourced from TM remote sensing image of Bayanbulak area in2000 and 2010,precipitation and temperature data from 2000 to 2007,survey and some public data in Hejing County. This paper offered some reference in Ecological Security Alarm of heritage site,wetland protection policy and rational development of animal husbandry. The results show that: ① study area landscape structure had changed,high coverage grassland area decreased by 39.63% with the most change in all classes. The low coverage grassland patch number decreased,shaped large connected to the whole area. Fragmentation index of dry land,river,marsh,high coverage grassland reduced but separation degree increased. Interference degree in middle coverage grassland increased. All those change in landscape caused by overgrazing in this area. ② The ERI was decreased overall but local increased about 40%. The study area was divided into five categories by ERI. The highest ERI region dispersed from a single center concentration to the multi-center distribution,and the acreage decreased34.01 square kilometers. The higher ERI region presented discrete distribution with the acreage increasing 222.74 square kilometers. The most middle ERI region was changed to higher ERI region,and the acreage of lower ERI region and lowest ERI region had little change. ③ The gravity center of all five ecological risk regions was moved from east to west. The distance of gravity migration was different,among lower ERI region was moved longest. ④ Climatic factors and human activity factors were the main driving forces for ecological risk index change in the study area. The climate change affects ERI indirectly by changing the hydrological characteristics of the wetland landscape types,plant and animal habitat area in the study area. Grazing,tourism and policy activities of human activities affected the pattern of landscape in small and medium scale. The policy factors changed the spatial pattern of the landscape types,improved the habitats of plants and animals,and the ecological environment in a short period of time.