Valuing the ecological effects is crucial to the assessment of output of the forestry project.This paper suggested an assessment system for the ecological effects of the land conversion project in Wuqi county

applying expert consultation

the layer analysis and the frequency analysis;and the paper also calculated the value of ecological effects from 1999 to 2004 using market valuation method

shadow engineering method

opportunity cost method

substitute expense method

among others.The results showed that the land conversion project in Wuqi county has produced tremendous ecological effects.The ecological value is up to about 2.48 billion yuan(RMB) in total

among which contributed by water resource conservation

soil conservation

air cleaning

microclimate improvement

farmland shelter and biodiversity increase are 0.64

0.60

0.53

0.03

0.002 and 0.67 billion yuan(RMB) respectively.The results may be a reference for the assessment of ecological effects of the land conversion project being carried out in the Loess Plateau.