A simple and effective method is developed to synthesize bimetal oxide@graphitized carbon nanocomposites composed of graphitized carbons, Ni-Co oxides, and a small amount of Ni and Co metals (denoted as NC x O@G, where x represents Ni/Co mole ratio), by in-situ thermal decomposition of their corresponding coordination polymers. The resultant NC x O@G nanocomposites exhibit excellent electrochemical performance such as high specific capacity and good cycling stability. Experimental results demonstrate that the Ni/Co mole ratio plays an important role in determining the electrochemical behaviors, and a small amount of Ni and Co metals can boost the performance. A maximum specific capacity of ca. 673.5Cg−1 at current density of 1.2Ag−1, a superior capacity retention (∼105% after 10,000 cycles at 10mVs−1), and a remarkable energy density of 46Whkg−1 with a high power density of 300Wkg−1 can be achieved when the Ni/Co ratio equals to ca. 1.0, signifying that this kind of nanocomposites are potential candidates for electrochemical energy storage.