Maize straw was hydrolyzed by acid which is in steam state and FeCl3 co-catalyzed process in a semi-batch tubing-bomb reactor system to produce furfural.Acid(such as acetic acid,formic acid and hydrochloric acid)and FeCl3 co Catalyzed process can promote the furfural yield.A series of experiments were carried out to investigate the effects of acid,FeCl3 concentrations and temperatures on furfural production.A maximum furfural yield of 72.89%(35.74%higher than that in conventional sulfuric acid-catalyzed process)was obtained at 180oC in the presence of 12g FeCl3 and 3%of acid.Acid and FeCl3 co-catalyzed hydrolysis was not only a high efficiency and environmental friendly technique,but also provided a possibility to utilize the furfural residue for ethanol production and other industries,such as ethanol production,levulinic acid production and so on.