Abstract: Precursor of lanthanum stannate（La2Sn2O7） was prepared by direct-precipitation method and ammonia sedimenta- tion method respectively，with La（NO）3·6H2O and Na2SnO3·3H2O as main raw materials.The precursor obtained by direct- precipitation method was tested by thermo-gravimetry analysis and was calcinated at different temperatures，then the corre- sponding calcinates were tested by X-ray diffraction（XRD） and the optimum calcination temperature（850 ℃） was confirmed. La2Sn2O7 was obtained by calcinating the precusor at 850 ℃.XRD and scanning electron microscope（SEM） results showed that all target products obtained by the above two methods were cubic crystal structure La2Sn2O7.When the pH=12，the target products obtained by ammonia sedimentation-calcination method and the products prepared by direct-precipitation-calcination method were spherical particles with diameters of about 50 nm，moreover，there were no obvious agglomeration between the particles.

Key words: lanthanum stannate, cubic crystal structure, precipitation-calcination method