The cationic polymerization of cis, trans-2,5-dihydro-2,5-dimethoxy furan (DHMF) was studied in the presence of HClO4, in acetonitrile. Different reaction parameters were investigated such as initiator concentration and temperature with duration. Obtained polymers were soluble in dimethylsulfoxide (DMSO) and dimethylformamide (DMF) and the M-n value was calculated as 2700 g/mol by cryoscopy. The FT-IR and H-1-NMR results indicate that the polymerization proceeds via ring opening. Thermal properties were studied by DSC and TGA.