Prepolymerizations employing an extremely high stereospecific and high active catalyst based on TiCl3 modified by di-n-butyl ether (DBE) were carried out with different monomers (styrene, propylene, hexene-1, cyclopentadiene). The influence of prepolymerization on the morphology of polypropylene obtained with TiCl3 catalyst was investigated. The catalyst was synthesized by TiCl4 reduction in toluene solution with AlEt3 . DBE complex. The polymer morphology was evaluated through optical and scanning electron microscopies and polymer bulk density and particle size distribution.