A series of carbon-containing cathode materials LiMnyFe1-yPO4 (0, y less than or equal to 1) were prepared using a solid-state reaction by adding carbon black to the synthetic precursors. The local structural change of electrochemically prepared LixMnyFe1-yPO4 (0 less than or equal to x less than or equal to 1, 0, y less than or equal to 1) samples has been investigated by X-ray absorption spectroscopy. The results showed that the local structural change of manganese is completely reversible during the charge-discharge processes. According to the analysis of K-edge X-ray absorption fine structure, no significant difference is observed in the local structure of manganese in the charged state over the entire manganese content range.