Abstract: In this thesis the author used the comparatice study to the desertification of three typical areas, located respectively at hyperarid, arid and semi-arid zones in Northern China and indicated the genesis and developmental processes of desertification in each area. Meanwhile, he tried to forecast the developmental trend of the processes in desertification by means of combining methods of the remote sensing and computer. The three typical areas are. Argan Region, Xinjiang(hyperarid zone); Jilantai, Inner Mongolia(arid zone) and Bashang Region, Fengning County, Hebei Province(semi-arid zone). According to the study, one can find that there are different causes and developmental process of desertification in different natural zones. For the Argan Region the main causes are, 1) misuse of water resources in upper and middle reaches of Tarim River. 2) overcollection of firewood and overgrazing. Because of these excessive human economic activities, Argan region located at the lower reach of Tarim Tiver has not water supplies in the river, as a result, the forest and grassland along the river have been degradated seriously; the flat sandy surface appeared shifting sands in patches and fixed sand dunes turned into shifting sand dunes. The encroachment of sand dunes promoted the expansion of desertified lands. Once desertified land is formed a vast area of shifting sand dunes appears. For Jilantai, the contemporary process of desertification mainly caused by the construction of salt mine and communication lines, collection of firewood and overgrazing. The results are encroachment of sand dunes under wind force, and blownsand spreaded into the salt lake, so the production of salt was influenced gravely. For Bashang region the main cause is over-cultivation, i, e., reclamation of steppe and enlargement of cultivated land areas. From the contrasting study, we can prove that the physical processes of desertification are similar in those typical region i. e., after the natural vegetation was destroied the strong wind acted on the uncovered land surface, landforns formed by blown sand got development through erosion, transport and deposition of wind force, meanwhile, the desertification occurred and are various in each area. Considering the different processes of desertification and resilience of ecosystem in each zone, one also can draw up different controlling measures to get the reversing processes of desertification. In Argan area, firstly, it is necessary to work out an overall programme so that one can utilise rationally all of water resource in upper middle and lower reaches, protect existing natural vegetation and dominate population growth the scale of agriculture and livestocks. In Jilantai, it is better to establish the synthetic protecting system for the salt mine and settlement by means of the combination of natural plants and artificial protective programme. In Fengning, the main controlling measures of desertification are: 1) to prohibit continuous over-cultivation to readjust existing landuse structure and increase the proportion of lands for forestry and animal husbandry. 2) to establish shelterbelts for protecting farmland and grasslands, and 3) to decrease population pressure. From the study, we think that the excessive human eoonomic activities are the dymainic factors which are direct causes of generation of the contemporary processes of desertification. Even though the world climate were changed at certain extent in the coming 59 years, it is impossible to transform the developmental trend of desertification in Northern China. So, one can say that the desertification is created by humankind and only can he harness it.