Abstract: Ambient background management was the basis for the determination of region-scale pollution status, assessment of environmental quality, forecasting of pollution and development of environmental standards. Issues related to background management were of critical importance to correctly interpret assessment data at potentially contaminated sites and properly discriminate possible anthropogenic inputs from background contributions. A lack of definition or a wrong knowledge of local reference background concentration for contaminants of concern may cause misleading conclusions on the classification of a site as potentially contaminated or overestimation of the contaminated volumes, and the background management strategy was therefore absolutely necessary for environmental site assessment procedures at potentially contaminated sites. A brief introduction to the methodology for determination of background values were made, and the influence of environment background assessment in environmental site assessment were briefed. The related basic information of background management and current international regulatory approaches and standard practices in Europe (Italy and Holland), USA and Canada were outlined.