The Siret River are used as raw water source for different municipal water supply systems, yet the Siret River are used as receiving bodies by some inhabitants and industry. In the study the quality of the Siret River water was determinate using a Water Quality Index (WQI). Results are presented from a field study performed on the Bistrita, Moldova, Suceava, Siret, Şomuzu Mare, Trotuş and Tributary River in the study area Siret Basin Romania. The main objective of this study was to determine is to find correlations land use to indicators physical-chemical of water quality, to investigate pollution source is more responsible for river water quality. This is of interest not only research context, but also for supporting and facilitating the application analysis postullend in the Water Framework Directive (WFD) (2000/60/CE) for the establishment of programmers of measures. For this purpose a slightly impact pollution source municipal wastewater treatment, land uses, urban, forest, agriculture and mining was selected and intensively monitored during six years January 2006 - December 2011, sampling was determined to meet the WFD standards for confidence in twenty two different control section of the Siret Basin. The main measures to reduce emissions to the Siret River were calcium, ammonium, sulfate, residue fixed (RF), sodium, chloride, free detergent and municipal wastewater treatment, concentrated on point emission. The main contributor to diffuse this parameters increased when more percentage of land was dedicated to industry and urban and less to forest and mining.