In this paper Poly (2-formyl pyrrole) (PFPy) was synthesized using hydrochloric acid as catalysis in alcohol. PFPy is green dark very fine powder. Then the polymer forms glass substrate in the reaction mixture. The resulting polymer was characterized by (FT/IR, EDX and XPS) to determine the polymer structure. The polymer was scanned by scanning electron microscope (SEM) and its film by AFM for its morphological properties. We found the polymer consisting of spherical particles with a rough surface (average diameters of 430 nm) and they formed clusters. We proposed a method for calculated particles size depending on the crystals size (by Scherrer equation) and percentage of crystallization of polymer from XRD. The average particles size is 336.7 nm. The particles size in this method may be closer to reality because the XRD includes a large number of particles and it not optional as SEM and AFM.