Li-rich cathode materials have attracted substantial attention because of their high energy density, but they still suffer from structural instability and voltage decay in cycling. Herein, a dynamic observation of the initial structural conversion and transformation is achieved by in situ Raman spectroscopy, and the effect of cut-off voltage on the intrinsic structure transformation is investigated by the using of three strategic charging protocols. The clear peak evolution related to the post-discharge spinel transformation is found that more obvious for the higher cut-off (4.8 V) protocol than for the lower cut-off (4.6 V) one after 300 cycles. In soft X-ray absorption spectroscopy, as demonstrated by the Mn L-edge spectra, more surface spinel-like Li1-xMnO2-δ (Mn3+) structure is formed as the cycle number and cut-off voltage increased, whereas the Ni L-edge spectra exhibited the same features throughout the cycling. The significant variations in the O K-edge also provide evidence distinguishing the structure transformation from the surface to the bulk material and the change in the lower cut-off protocol. Such spectroscopic analysis clearly confirm how the protocol control with an overall restricted charge cut-off voltage of 4.6 V significantly reduces the adverse effects of cycling on the oxygen plateau of the Li1.2Ni0.2Mn0.6O2 cathode.