The Xitieshan lead-zinc deposit is located at the northern margin of the Qaidam basin, Qinghai Province and is hosted in intermediate-basic volcanic-sedimentary rocks of an early Paleozoic rift basin. Several origins have been put forward for the deposit, including hydrothermal type, volcanogenic massive sulfide type and sedimentary-exhalative (SEDEX) type. It is now commonly accepted that the Xitieshan lead-zinc deposit is a SEDEX type deposit, with a complete marine sedimentary-exhalative system, including exhalative pipe facies, vent facies and sedimentary facies. The altered stockwork pipe is long and narrow, with >2 km in length and >200 m in width, and consists of mainly quartz albitite, thus representing the huge exhalative pipe facies. The wall rock marble extends to >3km in length and >1km in width with maximum thickness of >200m and is distributed outside of the altered stockwork rocks, hereby representing exhalative sedimentary rocks. The sulfide ore bodies have two modes of occurrence. One is as unstratified ore body penetrating the thick-bedded marble and is formed as a result of unerupted ore fluids filling and replacing the marble. It, together with the thick-bedded marble, forms the vent-proximal facies. The other is banded, stratified lead-zinc ore bodies occurring conformably between banded marble and calcareous quartz schist. It is far from the altered stockwork rocks and forms the sedimentary facies (Zhu et al., 2006；2007). Based on previous studies, in this paper we concentrate on fluid inclusions in carbonates associated with the unstratified ore bodies from both the exhalative pipe facies and vent-proximal facies and then discuss the relationship between fluid evolution and mineralization.