Detrital zircon is a key mineral for studying the evolution of early Earth orogenic belts. However, distinguishing between oceanic subduction and continental collision settings using detrital zircon rare earth element (REE) data remains an unresolved issue. This paper reviews previous experimental petrology studies and uses the Gangdese Mountains in Tibet as a case study to investigate the potential of the correlation coefficient (rDz) between detrital zircon europium anomaly (Eu/Eu*) and light/heavy REE ratios (LREEN/HREEN) as a discriminant for these tectonic settings. Experimental petrological studies indicate that the zircon Eu/Eu* and LREEN/HREEN are influenced by the crystallization processes of plagioclase and garnet, which are in turn controlled by crystallization pressure, protolith composition, oxygen fugacity, and magmatic water content of parental melts. These controlling factors exhibit variability across different tectonic settings, leading to the hypothesis that detrital zircon REE characteristics can be used to differentiate between them. To test this hypothesis, we analyzed detrital zircon REE data from the Tibetan Gangdese Mountains. During the oceanic subduction stage, Eu/Eu* and LREEN/HREEN show coupled evolutionary trends, resulting in a stable high rDz value of 0. 62~0. 81. This stability possibly reflects consistent oxygen fugacity and magmatic water content, a low abundance of S- type granitoids, and a dominant control of crystallization pressure on Eu/Eu* and LREEN/HREEN. After slab break- off and the transition to continental collision, rDz exhibits a significant decrease. The rDz values for 40~30 Ma, 30~20 Ma, and 20~10 Ma are 0. 73, 0. 57, and 0. 18, respectively. This decline is potentially due to a higher yield of S- type granitoids and more variable oxygen fugacity and magmatic water content, leading to decoupled evolution trends of Eu/Eu* and LREEN/HREEN. Our findings suggest that rDz has the potential to be a new proxy to distinguish between oceanic subduction and continental collision settings.