Optical recording medium and production method thereof

An optical recording medium consisting essentially of:

• a disc substrate having an uneven grooved pattern preformed on one surface thereof;
• an under layer formed on said uneven pattern of said disc substrate having a thickness of from 100 to 800 .ANG. , said under layer consisting essentially of a high polymeric material having a first temperature at which said high polymeric material can be melted, sublimated, or decomposed, a heat resistance superior to said disc substrate and a lower heat conductivity than said substrate;
• and
• a recording layer provided on said under layer, consisting essentially of a recording material having a second temperature at which said recording material can be melted, sublimated or decomposed;
• said first temperature being lower than said second temperature;
• said under layer being provided for relaxing thermal shock transmitted from said recording layer to said disc substrate.