Absorption spectra of soluble vanadyl phthaloeyanine Pr4VOPc (vanadyl phthaloeyanine with four propyl groups) in different medium were studied. Absorption due to the Pr4VOPc molecular monomers (λmax=706.0 nm) is dominant in dilute Pr4VOPe-chloroform solution. Absorption peak of the sublimed Pr4VOPc film is at 720.0 nm; whereas Pr4VOPc in solution east solid film shows a strong diffused absorption band ranging from 650.0 nm to 850.0 nm. In PMMA， absorption due to the molecular dimers is dominant (λmax=660.0 nm). This difference is caused by the great sterie effect between Pr4VOPc molecules. Pr4VOPc with strong near-IR absorption can be made by heating sublimed Pr4VOPc film or exposing it to organic solvent vapor. While only organic solvent treatment can make Pr4VOPc non-crystalline phase I in PMMA matrix change into crystalline phase II.