Abstract: All-solid-state thin film Lithium ion battery (TFLB) have great potential in micro-power applications. To obtain solid electrolyte layer, the LiPON thin film is usually used which can be deposited by radio frequency (RF) magnetron sputtering means. In this work, a LiPON thin film deposition method is investigated by the off-axis RF magnetron sputtering method under variable N2 working pressure. The experimental results show that LiPON solid electrolyte layer with Li＋ conductivity of 2.4×10－6 S·cm－1 can be obtained under the working pressure of 0.2 Pa. Additionally, the TFLB with structure of LiCoO2/LiPON/Li is fabricated using the optimized LiPON electrolyte. The discharge capacity of first cycle at 0.1 C is 62.1 μA·h·cm－2·μm－1 for TFLB, while 51.7 μA·h·cm－2·μm－1 at a higher rate of 4 C. Moreover, after 5 cycles of charge/discharge process at 0.1 C, 0.5 C, 1 C, 2 C and 4 C, the capacity retention ratio of 0.1 C for TFLB can still reach 90%.