In order to combat the developing trend of eco-environment degradation

a series of national environmental projects have been carried out in frail ecological zone since 1998. The construction measures adopted by the projects include handing farmland back to forestland or grass land

protecting nature forestry from deforestation

planting sheltering forest

conserving soil and water

and so on. To evaluate the effect of the projects on eco-environment

five sites in different eco-environmental zones were selected as study areas to monitor the change of land cover over 1997—2002. Through analyzing the change of land cover

it suggests that as a result of national environmental projects

the eco-environment is rehabilitating gradually except for the study area of East-northern China. The sheltering forestry has increased 1479 hm2

farmland has increased

and forestland and grassland decreased in the region of the case site located in East-northern China. In the region of the case site located in the north of Beijing

the total area resulted from the construction project is 51492 hm2

farmland has decreased

and forestland and grassland have increased. In the region of the case site in the north part of Shanxi Province

the total area resulted from the construction project is 11115 hm2

farmland has decreased

and forestland and grassland have increased. In the region of the case site located in the middle part of Gansu Province

the total area resulted from the construction project is 17437 hm2

farmland has decreased

and forestland and grassland have increased. In the region of the case site in Sichuan Province

the total area resulted from the construction project is 65347 hm2

forestland has increased

and farmland and grassland have decreased.