A homometallic mixed-ligand complex Pb(BTA)(phen)·H2O was synthesized by taking hydrated N,N′-bis(1H-tetrazolyl)amine (H2BTA·H2O), 1,10-phenanthroline (phen) and PbCl2as starting materials during this work. The complex was characterized by elemental analysis, IR, UV-Vis, FS and X-ray single-crystal diffraction. The results reveal that the coordination number of the Pb ion is four and the geometry can be regarded as a square-pyramidal geometry, with two N atoms of BTA2-and two N atoms of phen at the base. Crystal data for it, C14H11N11OPb, monoclinic, space groupC2/c,a= 9.420(2) Å,b= 22.943(6) Å,c= 15.286(4) Å,α= 90.000°,β= 105.760(4)°,γ= 90.000°,V= 3179.6(14) Å3,Z= 8, finalRindices [I> 2σ(I)],R1= 0.0241, wR2= 0.0471. The thermal stability of the complex was investigated by thermogravimetric analysis. The TG profile indicates that Pb(BTA)(phen) is thermally stable up to the temperature of 588.9 K.