Abstract: Objective To study the level of rare earth elements(REEs)content in children's blood and its affecting factors.Methods Blood REEs were determined by inductively coupled plasma source mass pectrometry(ICP-MS)in 112 children aged 7-10 years randomly sampled in the area containing rare earth(RE)ore and the control area in Xunwu county,Jiangxi and multiple regression analysis of blood REEs level was conducted on them.Results All 15 kinds of REEs were detected in each sample.The blood REEs content in RE ore area was 2.18±1.08ng/g and 1.73 times of the control area(1.26±0.35ng/g).The difference was significantly great(P<0.01).Seen from fifteen kinds of REEs,eleven kinds of REEs increased in children's blood in RE ore area,total light REEs content was 0.85 times higher and total heavy REEs content was 0.51 times higher than that in the control area.The difference was significant(P<0.01).Multiple regression analysis showed that distance from home to the RE area was the principal factor that affected the blood REEs content.Conclusion The blood REEs content would be higher if living a long time in the environment with high concentration of REEs.The blood REEs content can reflect the level of REEs content in human body to a certain extent.