A high molecular weight ladder polymer based on 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethylspirobisindane and 1,4-dicyanotetraflurobenzene has been synthesized by polycondensation under high-intensity mixing conditions at about 155 degrees C and cyclic-free products were obtained in high yield with low molecular weight distribution (1.7-2.3). The reaction could be completed within a few minutes. The polymer properties were characterized by GPC, H-1 NMR, C-13 NMR, F NMR, FT-IR, and MALDI-TOF MS. In addition, the mechanical properties, apparent surface areas and gas permeability are also reported. This procedure can also be used for the synthesis of other ladder polymers by irreversible polycondensations of tetraphenols with activated tetrafluoro aromatics.