Growth of nano sized Bismuth oxy chloride (BiOCl) and Bismuth Oxide (Bi2O3) thin film on glass was achieved by Metal Organic Chemical Vapour Deposition (MOCVD) method. It was synthesized from solutions containing Bismuth chloride (BiCl3) in Acetone and Bi(NO3)3:5H2O in 1M HNO3.The BiCl3 solution was carried by nebulisation effect by Argon gas and Bi(NO3)3:5H2O by Oxygen in the reactor. The temperature degrades the chemical composition into nano thin films of desire particles on the glass surface. The expected reaction is mentioned below. NPs growth takes place on glass substrate at 600°C. Self assembly of BiOCl and Bi2O3 crystals were observed on the glass substrates. Obtained thin films were characterized by Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS). Further, thin films of BiOCl and Bi2O3 were evaluated for photocatalytic study. BiOCl NPs thin film was tested against methyl orange dye and Bi2O3 thin film was tested against Acid blue 113 dye under UV light. Analysis results are interesting, 90 % of dye absorption was observed in both the films. As this is the preliminary expt. on growth and dye degradation study with both the films, the data is not comparable. The study only confirms the preliminary observation on dye degradation by UV-vis spectroscopy. Further, the detailed study is in a process