A new borate [Ni(dien)2][B5O6(OH)4]2(1,dien = diethylenetriamine) has been hydrothermally synthesized and structurally characterized.The crystal structure of compound 1 crystallizes is of monoclinic system,space group C2 with a= 14.498(3),b = 11.757(2),c= 8.5455(17),β= 90.93(3)o,V = 1456.4(5)3,Z= 2.Compound 1 consists of borate polyanion [B5O6(OH)4]-and complex cation [Ni(dien)2]2+.The anionic [B5O6(OH)4]-units are linked by O-H…O H-bonds to form a 3-D supramolecular network with 1-D large channels,where the [Ni(dien)2]2+ cation are located.The optical absorption spectrum indicates that compound 1 is wide-band-gap semiconductors.