A　new　bismuth　oxalate　Na(C5NH6)[Bi(H　2O)(C2O4)2]2-　·4H2O　has　been　obtained　under　hydrothermal　conditions　and　characterized　by　X-ray　diffraction.　It　crystallizes　in　mono-clinic,　space　group　C2/m　with　a　=　12.020(5),　b　=　11.190(8),　c　=　11.067(10)　Å,　β=　121.78(2)°,　NaBi2C13NH18O22,　Mr=　981.24,　V=　1265.4(16)　Å3,　Z=2,　Dc　=　2.575　g/cm3,　μ(MoKα)　=　14.005　mm-1,　F(000)　=　912,　R　=　0.0179　and　wR　=　0.0394.　In　the　structure,　the　Bi(III)　centers　are　interconnected　by　oxalate　ligands　to　produce　honeycomb-like　layers,　which　are　further　pillared　by　bridging　ligand　oxalate　molecules　to　form　a　3-D　open-framework　structure.　Furthermore,　the　title　compound　exhibits　blue　luminescence　with　the　emission　peaks　located　at　394nm　in　the　solid　state　at　room　temperature,　and　thus　it　could　be　useful　in　the　field　of　photoactive　materials.