For the successive total utilization of lignocellulosics, the phase-separation system has been developed. A key of this system is the phase-separation treatment with phenol compounds and concentrated acid. Without heating and pressing, the cell wall with IPN structures is separated into the lignin-based polymers (lignophenols) and carbohydrates within 1 hour. The functionality of materials can be controlled by the properties of phenol and acid in the phase-separation system. The lignophenols had unique properties that conventional lignins did not have. Furthermore, the functionality of lignophenols was controllable using the intramolecular switching function (cleavages of C2-aryl ether linkages by nucleophilic attack of C1-phenolic nuclei to C2). The carbohydrates can be converted to functional oligo-saccharides, simple sugars, alcohols etc. The phase-separation system would form the basis of an advanced molecular-level refining and recycling system for forestry products.