Abstract: Humic acids (HA), which can affect the environmental behaviors and toxicological effects of organic contaminants, are a critical fraction of natural organic matters (NOM) in soil and/or sediment. A clear understanding of sorption of organic contaminations to humic acids would be helpful in determining their sorption mechanisms in soil and/or sediment. Using batch equilibrium method, the kinetics and thermodynamics of ben zotriazole (BT) adsorption on HA were investigated. The results show that the kinetic data were well described by the pseudo second-order kinetic model. The adsorption was rapid in the beginning and then was followed by a slowly increasing period. BT was quickly adsorbed during the first 40minutes, and the total amount of adsorbed adsorbate reached above 89.0% of the sorption amount at equilibrium for all the treatments. The adsorption isotherms could be described by Freundlich models with high R^2values of 0.9996-0.9999. The solution temperature was negatively correlated with the adsorption rate. When the temperature increased from 288.15K to 308.15K, the amount of adsrobate adsorbed decreased from 15.70g/kg to 11.58g/kg, Furthermore, during the adsorption process, ΔH0was -30.19kJ/mol, indicating that the adsorption was exothermic. The negative ΔG0suggested that the adsorption process was spontaneous. The E_a parameter was obtained by the Arrhenius Equation; the activation energy in this study was 19.35kJ/mol, indicating that BT adsorption by HA is a typical physicals adsorption.