Abstract: Cracking methyl tertiarybutyl ether (MTBE) is a promising routine for producing isobutylene of high purity. In an integral tubular reactor, the process is studied over the solid heteropolyacid catalyst SPC01 under various liquidvolume space velocities (0.5—2.0 h-1), pressures (0.2—0.6 MPa) and temperatures (160—230 ℃). The effects of the operating conditions on the cracking process are discussed. The conversion of MTBE reaches 92.2% and the selectivities of isobutylene and methanol are both over 99.9% at the reaction temperature, pressure and liquidvolume space velocity of 210—230 ℃, 0.4 MPa and 0.5—1.0 h-1, respectively. Plug flow reactor model is applied to establish powerlaw kinetic model, and the parameters in the model are evaluated by fitting the experimental data with the method of least squares. The calculated results from the model are in good agreement with the experimental data.