In this paper, Bioconcentration and elimination of five light rare earth elements(KEEs) La, Ce, Pr, Nd and Sm were investigated in carp (Cyprinus carpio L.). The results show that internal organs had high ability to bioconcentrate light REEs. The order of BCFs of REEs was mostly internal organs >> gills>skeleton>muscle, there were slight differences among the BCF values of different REEs in a given tissue. In the elimination process, there were two patterns of elimination, the pattern of elimination in giIlsskeleton and muscle could be descn'bed by two-compartment model and the pattern of elimination in internal organs could be divided into two periods, the second period could be described by one-compartment model The biological haft-lives (Tb) of each REEs in tissues of carp were obtained. The results also indicated that internal organs were considered to be the most important site of light REEs' detoxification and metabolism.