In order to simultaneously detect the multi-solute concentrations in mixed solution, system for measuring the multi-solute concentrations in mixed solution using optical Fiber Fabry-Perot Resonator(FFPR) is proposed. The relation between FFPR interference transmission wavelength and concentrations of the mixed solution is analyzed theoretically. The measuring system consists of an InGaAs LED, fiber coupler, FFPR sensor, opto-electrical convertor, amplifier and spectrometer. The analytical equation between concentrations and interference transmission wavelengths is standardized by measuring the samples contain ethanol and glycerin. The action script 2.0 is used as the programming language according to the mathematical relation. The real-time variation of the concentration change is monitored by the PC.