A new binuclear nickel(II) complex Ni(HPT)(HO)(1) has been hydrothermally synthesized with nickel hydroxide,3,4-pyridine dicarboxylic acid and 3-(pyridin-2-yl)-1,2,4-triazole (HPT) in the mixed solution (the volume ratio of methanol and water is 1:4).It crystallizes in tetragonal space group P4/n,with a=20.844(1),b=20.844(1),c=7.2463(7)?,V=3148.2(5)?~3,D=1.587 g/cm~3,Z=4,μ(Mo Ka)=1.257,F(000)=1544,the final GOOF=1.043,R=0.0437 and w R=0.1297.The crystal structure shows that the whole molecule consists of two nickel ions which are bridged by fourμ-η~1:η~0-3-(pyridin-2-yl)-1,2,4-triazole anions.The coordination environment of Ni(II) ion is Ni N,giving a distorted octahedral geometry.The thermal stability and fluorescent and magnetic properties of the complex were investigated.