Zhang Yinhuan was a famous diplomat in modern China.In the Sino-Japanese War's peace negotiation in 1894, Zhang Yinhuan positively participated in the peace negotiation plan, and was deputed negotiation minister to Japan.The Japanese refused the negotiation for "the plenary powers insufficiency" of the Chinese peace negotiation ministers.The article analyses the reasons of Zhang Yinhuan's being refused as peace negotiation minister from the two aspects of China and Japan.After returning to homeland, Zhang Yinhuan continued to assist Li Hongzhang's peace negotiation to Japanese, and played an influential role.