Inductively coupled plasma_mass spectrometry (ICP_MS) is used to determine rare_earth elements abundances in fluid inclusions. Quartz separates from the Lannigou and Yata Carlin_type gold deposits, southwestern China, were prepared by the decrepitation_leach method. Leachates were analyzed by ICP_MS, using conventional sample introduction. The results demonstrate that the decrepitation_leach method, in combination with ICP_MS analysis of leachates, is effective for REE determination. The chondrite_normalized REE patterns of inclusion fluids for the Lannigou and Yata samples associated with gold mineralization are characterized by light rare_earth elements (LREE) enrichment, with a weak negative Ce anomaly and a positive or negative Eu anomaly, whereas the pattern for the Lannigou sample associated with late gold mineralization (quartz_calcite stage) is characterized by LREE enrichment relative to HREE, with negative Ce and Eu anomalies.