LaF3 superfine powder was synthesized from LaCl3.7H2O and NH4F by microwave method, using methanol or de-ionized water as dispersants respectively. The results ofXRD, TEM, and SEMindicate that the superfine powder has high purity, regular particle shape, and narrow distribution of granularity. The granularity of the best sample is in the range of 10-20nm. Compared with traditional preparation methods of LaF3 powder, the advantages of microwave heating method was summarized. The powder belong to hexagonal symmetrywith a =7.182A.U, and c = 7.254A.U. Rapid synthesis with near uniform diameter of lanthanide based nano crystals has been achieved.