Imidazolium predicated room temperature tri-cationic ionic liquid (RTILs) shows highly efficient and selective dehydration of fructose, sucrose, and glucose into 5-hydroxymethylfurfural (5-HMF). The formation of 5-HMF has been investigated using different reaction parameters, such as catalyst weight, reaction time and temperature. Among different reaction parameters, 93% yield of 5-HMF was obtained from fructose in [GLY(mim)(3)][OMs](3) at 120 degrees C within 2 h, while 72% and 51% yield of 5-HMF were achieved from dehydration of sucrose, and glucose respectively at 120-140 degrees C in 3h to 5h. In addition, the effect of reaction time, molar ratio, and temperature with CC-SO3H co-catalyst have been discussed. In which, 97%, 77%, and 58% yield of 5-HMF were obtained from fructose, sucrose, and glucose, respectively, in the presence of [GLY(mim)(3)][Cl](3) and CC-SO3H catalyst at 130-140 degrees C within 3-5 h. Both catalytic systems showed excellent recyclability for carbohydrates to 5- HMF conversion without any loss in its catalytic activity. [GRAPHICS] .