The disclosed invention proposes a Heparin Prefilled Syringe Made of Cyclic Olefin Copolymer or Roselene Crystal Clear polymer for exact Heparin dose administration. The present Heparin prefilled syringe made of Cyclic Olefin Copolymer or Roselene Crystal Clear polymer do not retain heparin molecules to the walls of the said syringes as the said syringes are siliconized and do not allow the negatively charged heparin to get attached to the walls of the syringe. Therefore, there are no chances of fluctuation in the dosage. Also, the present Heparin prefilled syringe made of COC or RCP being prefilled, contain premixed Heparin and Sterile Water in the relative amount for the required dose and so do not require them to be mixed from the ampoules prior to administration. Therefore, the possibility of fluctuations in dosage is considerably reduced. Further, there are no risks of dosage fluctuation due to handling errors as it is not required to be filled from the ampoules. Hence, there are no risks of heparin getting contaminated.