Construction site of rocky slope surrounding Zhujiajian airport of Zhejiang Province was selected as the study site.Synthetic soils were constructed by adding chicken manure(CM) and peat soil(PS) with 12 different ratios.Based on the analyses of soil texture and aggregate composition,11 anti-erodibility parameters,which can be further classified into four groups including inorganic clay,micro-aggregate,water-stable aggregate and organic colloid,were calculated and compared.Principal component analysis was then applied to determine the contribution of each anti-erodibility factor.Furthermore,the anti-erodibility of the synthetic soils with organic amendments was evaluated.The results showed that the anti-erodibility indicators should be re-grouped into three categories: microaggregate,inorganic clay,water-stable aggregate,in which aggregation degree,aggregation status,dispersal rate were the best indicators for assessing anti-erodibility.As the PS group could not meet the minimum requirement of principal component analysis,no quantitative evaluation of anti-erodibility was conducted for the synthetic soils with different mixing ratios.Linear function analysis of the principal components and composite indicators showed that synthetic soils of the CM group have the best anti-erodibility with soil∶CM ratio of 2.41(weight basis).