The present invention relates to organic anti-reflective coating polymers and preparation methods therefor. Anti-reflective coatings are used in a semiconductor device during photolithography processes to prevent the reflection of light from lower layers of the device, or resulting from changes in the thickness of the photoresist layer, and to eliminate the standing wave effect when ArF light is used. The present invention also relates to anti-reflective compositions and coatings containing these organic anti-reflective coating polymers, alone or in combination with certain light-absorbing compounds, and preparation methods therefor. When the polymers of the present invention are used in an anti-reflective coating in a photolithography process for forming submicro-patterns, the resultant elimination of changes in CD due to diffractive and reflective lights originating from lower layers increases the product yield in the formation of submicro-patterns during the manufacture of 64 M, 256 M, 1G, 4G and 16G DRAM semiconductor devices.