A variant of all-resonant CARS named electronic-resonant enhancement CARS(ERE-CARS) is applied to measure the methanol-water solution concentration at room temperature.The measurements are performed using the ERE-CARS signal of the Raman vibrations near the C-H stretching modes(at 2835 and 2942 cm 1) in methanol.By changing the timing(t>0) of the laser pulses of this non-degenerate four wave mixing technique,the concentration information based on the vibrational dynamics of the C-H bonds can be successfully detected as the frequency-spread dephasing rate during the first few hundred fs in the ERE-CARS signal with high sensitivity and accuracy.Femtosecond time-resolved ERE-CARS technique is applied to the concentration analysis of a mixture of the organic solution.This investigation indicates that femtosecond time-resolved ERE-CARS technique might be a powerful tool for real-time detection for solution concentration of different liquids.