A new study of the absorption bands of the Schumann-Runge system of molecular oxygen, which overlap the Herzberg continuum is made in order to improve the aeronomic calculations in the mesosphere and stratosphere. After a complete analysis performed at high resolution of the rotational structure from the (0-0) band at 2050 Å to the dissociation limit at 1750 Å, absorption cross section values for various rotational lines are measured from 2011·63 to 1763·66 Å using emission silicon lines of which wavelengths are known with high precision. The absorption cross sections are obtained with a 0.5 cm-1 resolution taking into account the rotational line shape due to predissociation, Franck-Condon factors and electronic absorption oscillator strengths.