As an important tracer, REE is widely used to trace provenance of various sediments and sedimentary rocks. This paper firstly describes the characteristics of REE, then summarizes REE abundance and distribution patterns in seawater, freshwater , sedimentary rocks and sediments, and theirmain controlling factors. At lastthe application and problems of REE as a source rock tracer are also described in detail. Weathering of source rock can produce REE fractionation, especially during strong chemical weathering; Transport of particles and hydrodynamic sorting during formation of sediment also have potential influences on REE characters in sediment. REE abundance and patterns are different in different grain-sized sediments. It is generally regarded that clay has REE compositionmost close to source rock, whereas sandy sediment differentiates fromsource rock inREE composition, because detritusminerals can alsoobviously influence REE content and distribution patterns in sediment. REE normalizing and determining problems are discussed in the end of the paper.