Platinum thin films grown by chemical vapor deposition (CVD) using a liquid precursor of (methylcyclopentadien-yl)trimethylplatinum were characterized in terms of crystallographic nature, morphology, contaminants, and their influence on electrical properties. The lattice constant of these CVD films (3.91-3.92 Angstrom) is smaller than that of bulk platinum. A high oxygen contaminant is observed, irrespective of the oxygen ratio during growth. A film grown at low oxygen content consists of randomly oriented micro-grains and contains a large amount of carbon contaminants. When the film is grown under oxidative conditions, it shows a 111-textured cylindrical morphology with increasing thickness, The electric resistivity is higher than the bulk standard, and it increases with decreasing oxygen ratio during the film growth. These results indicate that the carbon contaminant causes the randomly oriented micro-grains and contributes to the high residual resistivity.