A simple two-step process was conducted to scrutinize new catalytic action of chromium fluoride (CrF 3 ) by evaluating its effect on the yield of hydroxylmethylfurfural (HMF) in ionic liquid (1-octyl-3-methylimidazolium chloride) using raw tapioca root biomass with high starch, and hydrolysis efficiency of the biomass extract was characterized by FT-IR spectrometry and FESEM image analysis. The FT-IR absorbance bands confirmed the presence of starch and other soluble sugars in the acidic biomass extract by presenting its frequency signals in the 950–1200cm −1 regions. FESEM image showed that the efficiency of the biomass hydrolysis is time-dependent. The concentration of CrF 3 significantly affected the yield of HMF. Its highest yield (52.6±4.8dwt%) was achieved at 1% CrF 3 , but over 1% CrF 3 its yields began to decline. The combined addition of CrF 3 and CrBr 3 showed ca. 1.3-fold higher yield than CrF 3 alone. The reaction rates of HMF synthesis were considerably influenced by the stoichiometry ratio of CrF 3 to biomass. The highest reaction rate (0.41g/g biomass/h) occurred at 0.2 ratio value.