It is an object to provide a method in which a lignocellulosic material is treated with a phenol derivative and acid, whereby a lignophenol derivative can be recovered, and moreover sugar from an acid/sugar solution obtained at the same time can be recovered and used easily and efficiently. One form of the present invention relates to a method of separating and recovering an acid/sugar solution and a lignophenol derivative, comprising putting a reaction mixture of a lignocellulosic material, a phenol derivative and an acid into an amount of water 0.5 to 6 times the amount of the mixture as a volume ratio, and leaving the mixture to stand or maintaining the mixture in a weakly agitated state, so as to agglomerate a lignophenol derivative produced as a solid phase, and then carrying out solid-liquid separation, so as to separate and recover the lignophenol derivative as the solid phase and an acid/sugar mixture as a liquid phase.