Crystalline rare-earth (RE) carbonates having large particle size were prepared from the lixivium of weathered crust elution-depos-ited rare-earth ores using the precipitation method with ammonium bicarbonate as the precipitant. Their chemical composition was studied us-ing elemental and thermogravimetric analyses (TGA), and their structure and morphology were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrate that the crystalline rare-earth carbonate is a hydrated basic carbonate or oxycarbonate and not astable intermediate carbonate in the process of thermal decomposition. The particle size of crystalline rare-earth carbonates with large particle size is in the range of 50-200 μm. With an RE2O3 content of up to 95wt％, the quality of crystalline rare-earth carbonates is higher compared to the Chinese National Standard (GB/T 28882-2012). The quality of the product is superior to the Chinese National Standard.