Aiming at replacing the common(noxious)solvents,ionic liquids have been recently researched for the dissolving of lignin,specifically the deep-eutetic solvent(DES,one kind of ionic liquids),and using the modified lignin as phenol-formaldehyde(PF)resin filler to synthesis new PF resin with better performance.In the present work,a series of mixtures of zinc chloride/acetamide with different molar ratios was prepared to obtain DES.The structural changes of DES compared with acetamide were investigated by Fourier transformed infrared,it was found that the formation of DES occurs through oxygen and metal ion.Observed from the physical properties of DES and the viscosity,the preferable molar ratio of ZnCl2/CH3CONH2 was 1:3.Original lignin was dissolving in DES above,and subsequently regenerated using water.The structural changes of the original lignin and regenerated lignin(RL)were analyzed by Fourier transformed infrared,UV-Vis,1H Nuclear Magnetic Resonance and Scan ning electron microscopy,Thermal Gravity Analysis,2D Heteronuclear Multiple Quantum Correlation NMR).The RL obtained in DES(mass ratio of 1:10 for 4h)higher yields than any other mass ratio and reaction time by water regeneration.This indicated that extending reaction time and increasing the mass of DES made the condensation rate of lignin greater than the rate of degradation,which could be seen from the color of the supernatant of DES-water system.The color(reaction time for 2h)was deeper due to more degradation of small molecule from lignin,which consistent with the results of the 1H spectra of the recovered DES.The total content of phenolic hydroxyl increased about 28.9%in RL compared with original lignin,suggesting that the reactivity of lignin could be improved after pretreated by DES.Thermo gravimetric analysis demonstrated significant differences in the thermal behavior of the RL as a result of DES treatment.The results indicated that the RL has a higher thermal stability than the original lignin,which was possibly related to the formation of PF resin.PF resin containing the RL exhibited similar bonding strength and shorter Sunshine gel time than common PF and common PF with original lignin,indicating that the zinc(II)catalyzed the polymerization of PF resin and accelerated the curing of the resin.