Two new copper (II) complexes [Cu(2-Pic)2(4-NPA)2] (1) and [Cu(2-Pic)2]·2H2O (2), where 2-Pic is 2-picolinic acid and 4-NPA is 4-nitrophenylamine, are synthesized hydrothermally and their crystal structures are determined and analyzed. Complex 1 is crystallized in the monoclinic system space group P21/c and complex 2 is in the triclinic system space group P-1. Single crystal X-ray analysis reveals that the coordination environments around the Cu atoms of two complexes are four-coordinated and sixcoordinated respectively. Complex 1 forms a 2D layer of a supermolecular structure through hydrogen bonds, and complex 2 is a 1D stair-stepping polymer chain and two water molecules linked by a hydrogen bond intersperse among the chains.