The present paper deals with a comparison of regression equations for describing arsenate adsorption by soils.Five soils including manured loessial soil,loessial soil and yellow brown earth collected from Shaanxi Province were used in experiment.The results obtatined has shown that Freundliche equation fits better for the experimental data than those and the revised ones of Temkin and Langmuir.The As adsorption curve derived from Freundliche equation is identical with the trend of variation of As adsorption measured directly,its standard deviation (S) is minimum(4.3-39.4),and the correlation coefficient (R²)is maximum(0.91-0.99).The curves derived from other equations differ greatly from their respective values measured directly.