Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">Production of hydrogen peroxide by anthraquinone method was significantly influenced by tetrahydroanthraquinone in the working solution.The formation law of tetrahydroanthraquinone during the cycling of working solution was summarized by studying its formation reasons,physical-chemical properties,principles of hydrogenation and oxidation reaction in hydrogen peroxide production as well as researching and contrasting start-up/running conditions of different plants.The forming quantity of tetrahydroanthraquinone was decided on catalyst,carrier,solvent,operation conditions and activated alumina to some extent.Effect of tetrahydroanthraquinone on hydrogen peroxide production and advantages/disadvantages about its content were described.Methods for controlling its excessive content were also brought forward.</SPAN>