A new Ni(II) complex, [Ni(H2O)6]•(L) (L=1,5-naphthalenedisulfonate) has been obtained by the reaction of Ni(OAc)2•4H2O with sodium 1,5-naphthalenedisulfonate in the CH3CH2OH/H2O (V:V=1:1) solution. The complex was characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results showed that the local geometry around central Ni(II) ion can be described as distorted octahedral environment which connected by six coordinated water molecules. The complex molecules formed one dimensional chained structure by hydrogen bonds and π-π stacking.