Abstract: The process flowsheet for the removal of radioactive nuclides from lanthanum oxide is given and pilot-plant scale experiment is completed in Shanghai Yuelong Chemical Plant. The results indicate that decontamination factors of a-radioactivity, iron and calcium are higher than 1000, the recovery of lanthanum is greater than 96%, a-radioactivity in La2O3 product is lower than 1 count per hour, and Fe2O3 and CaO content are lower than 5 ppm. High quality phosphour grade La2O3 is obtained.The results show that this technological process is feasible and reliable.The operation is simple and stable.