Ultra-thin polymer films containing cobalt(II) meso-tetraphenylporphyrin(CoTPP) have been prepared by vacuum codeposition of the metal complex and trans-2-butene as an organic monomer using an inductively coupled RF glow discharge operating at 7-9 Watts. The polymer films were characterized by sorption measurements. Sorption data obtained for polymer films containing CoTPP indicate that the CoTPP molecules are capable of reversibly binding oxygen molecules. It was found that the adjacent CoTPP molecules in the aggregated metal complex phase could irreversibly share the oxygen molecules. A dispersion of the metal complex molecules in the polymer matrix was made to maintain the reversible reactivity of the metal complex molecules with oxygen in the polymer films via vacuum evaporation process. The Henry mode solubility constant, the Langmuir mode capacity constant, the amount of binding oxygen, and the dissociation equilibrium in the dual mode sorption theory were discussed.