Land use spatial allocation is a space optimization to improve the land use efficiency by distributing different land use types under the limits of regional land use structure according to specific planning objectives in spatial and temporal scales(Zhang et al.2012).It is very complex because it need to consider not only numerous spatial factors,attributes and constraints,but also multiple and often conflicting objectives(Chen et al.2010 and Cao et al.2011).Therefore providing an effective method for decision-makers to determine effects and costs of solutions in different scenarios becomes increasingly important(Loonen et al.2007).