Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China. It is important to study the evolution of landscape patt to curb its environmental degradation. In order to intuitively show how the landscape patt of the study area changes over time, Landsat Thematic Mappers (TM) and Landsat Operational Land Imager (OLI) data of 1991, 2000, 2010 and 2017 were used. This paper attempts to apply niche theories and meth-ods into landscape ecology, and constructs a niche model of landscape components by using n-dimentional hypervolume niche theory and landscape patt indices. By evaluating the spatial and temporal evolution of niche from the perspec-tive of two-dimensional space to reflect the changes of landscape patt in the study area over the past 26 years, new the-ories and methods were introduced for the characterization of landscape patt. The results indicate that: 1) The larger the attribute and dominance value of landscape components, the higher the ecological niche and the stronger the control effect on the overall landscape. 2) The ecological niche of each landscape component was significantly different, just as its con-trol effect on the overall landscape. 3) The dynamic change of the ecological niche of each landscape component was dif-ferent, with grassland, unused land and arable land always in a high dominant position, although the ecological niche of construction land and water area was always low. In general, the introduction of niche theory into the landscape ecology provided a new method to study the changes in regional landscape patt.