The quality of ecological environment in Beijing City and its surrounding areas has been improved since the Beijing-Tianjin sandstorm source control project was launched.And a scientific and reasonable method is needed urgently to evaluate the effects of the project.A remote sensing evaluation system for ecological environment quality was established based on previous research foundation and special circumstances in Beijing-Tianjin sandstorm source area.The improved Delphi method was employe

and a weigh coefficient was introduced.By comparing the mean value and standard deviation of the number of points given by two groups of experts

the weights of evaluation factors could be determined according to different evaluation perspective.Based on this

the remote sensing evaluation model of ecological environment quality suitable for Beijing-Tianjin sandstorm source area was established.Evaluation scroce calculated from the established model for the study region was 4.13

which corresponded with the current level of this region.However

evaluation results from the traditional remote sensing quantitative model showed that mild desertification area account for 28% and moderate desertification area account for 35%

which exaggerated the deterioration degree of ecological environment in study region.