Layered Li1+x (Ni0.3Co0.4Mn0.3)O2−δ (x =0, 0.03 and 0.06) materials were synthesized through the different calcination times using the spray-dried precursor with the molar ratio of Li/Me=1.25 (Me=transition metals). The physical and electrochemical properties of the lithium excess and the stoichiometric materials were examined using XRD, AAS, BET and galvanostatic electrochemical method. As results, the lithium excess Li1.06(Ni0.3Co0.4Mn0.3)O2−δ could show better electrochemical properties, such as discharge capacity, capacity retention and C rate ability, than those of the stoichiometric Li1.00(Ni0.3Co0.4Mn0.3)O2−δ . In this paper, the effect of excess lithium on the electrochemical properties of Li1+x (Ni0.3Co0.4Mn0.3)O2−δ materials will be discussed based on the experimental results of ex situ X-ray diffraction, transmission electron microscopy (TEM) and galvanostatic intermittent titration technique (GITT)