The barite and the behavior of REE in its crystallo-chemical structure have been a major category of research done by scientists for a long time. There are various barite mineralization in Northwest Iran. These sediment-hosted resources as a type of tectonic-controlled-vein mineralization bear unconformity to their shale host rocks at Precambrian age (Riphean). The REE geochemical studies are carried out with the aims to investigate the behavior of REE in barite and galena crystal chemistries and to compare them with respect to their host rocks and some certain standards to reach the aims, Eu, Ce, La anomalies, chondorite normalized ratios, and other standards are used. REE evidences revealed discrepancy between barite-galena mineralization and host rocks. Barite crystallized at oxidized environment, but galena at reduction environment; moreover, barite originated from volcanic sources. Finally it seems that the mineralizations are formed under brine and hydrothermal fluid mixing condition.