The bad soil and water loss, land degradation caused extreme difficulty and harm for local production, ecology, society development and people's living at loess plateau in the Southern Ningxia. Therefore, to reconstruct the environment and promote the development of society become out of most urgent tasks in the local government. Chengjiao and Majian Town of Xiji County are the typicall areas of arid-semiarid loess mountain ridge area, it is impossible for some areas to rely on it's own strength to reform ecology. So it's necessary to carry out the ecologyical rehabilitation based on the investigation and scientific research, management and plan, and to increase related external input. This paper has analyzed the principal ecological environmental questions of arid-semiarid loess mountain ridge area based on the ecological geological investigation in Chengjiao and Majian Town of Xiji County, and has summarized the ecological construction modes fitted to this area by the geology, geomorphology, climate and vegetation of this area, i.e, the high effective ecological agricultural construction mode, the agricultural construction mode of the economic horticultural management of complex agriculture-orchard, the ecological agricultural construction mode of grass-shrub-forestry farming and the forestry-grass-shrub complex ecological mode.