Phase-pure Eu3+ doped Gd2Sn2O7 nanocrystals have been successfully synthesized via a co-precipitation processes combined with hydrothermal treatment. The crystal structure, particle size, morphologies, composition, and photoluminescence properties of the as-synthesized products were investigated by XRD, SEM, TEM, EDS and PL. The samples were single-phase cubic pyrochlore-type nanocrystals with a typical size of about 30 - 60 nm. All the samples exhibited irregular flower like secondary nanostructure assembled by primary nanoparticles. Photoluminescence properties of Gd2Sn2O7:Eu3+ were investigated, and the results revealed that the as-synthesized materials displayed intense and prevailing emission located at 580 - 630 nm. The excitation spectra indicated that an energy transfer from Gd3+ to Eu3+ occurred. Meanwhile, the concentration quenching phenomenon was observed in Gd2Sn2O7:Eu3+nanocrystals.