The absolute absorption cross sections of the (2, 1)--(12, 1) Schumann-Runge bands of O2 at room temperature have been obtained from measurements of the total absolute absorption cross section arising from transitions from the ground-state levels with v'=0 and 1 by subtraction of the v'=0 contributions, which have been synthesized from our previous determinations of the band oscillator strengths, line center positions and predissociation line widths of the (v', 0) Schumann-Runge bands of O2. The resultant absolute absorption cross sections of the (2, 1)--(12, 1) bands have been integrated numerically to obtain the band oscillator strengths. Our experimental band oscillator strengths are somewhat lower than the expermental values of Lewis et al. (1986) but are in good agreement with the recently calculated values of Friedman (1990). ¿ American Geophysical Union 1990