Excited state population distribution of 5S_1/2 →5P_3/2 with laser excitation in room temperature rubidium vapor mixed with H₂ was quantitatively analyzed by absorption and saturation spectroscopy.When the laser linewidth is much smaller than the Doppler linewidth,the absorption coefficients were measured for a series of laser powers between 40 μW and 5 mW at 780 nm. Population in the 5P_3/2 level obtained from the saturation measurements was also determined by the absorption measurement of narrow spectral line from a Rb hollow cathode lamp. The results obtained in these two ways arin good agreement.When the H₂ pressure was 100 Pa,it was shown that 8% of the ground state population could be transferred to the first excited state by pumping the Doppler broadened line with a single-mode narrow-band laser.