The effects of ethanol solutions on lower power Ar ICP discharge were studied by measuring plasma temperatures (gas temperature, excitation temperature, ionization temperature and electron temperature) and electron number densities. The temperatures and electron number densities were reduced with the increasing of ethanol concentration. The ICP system is much apart from LTE conditions. Thus, ethanol solutions will place a reducing effect on spectral line intensity. The effects of ethanol solutions on lower power Ar ICP discharge were studied by measuring plasma temperatures (gas temperature, excitation temperature, ionization temperature and electron temperature) and electron number densities. The temperatures and electron number densities were reduced with the increasing of ethanol concentration. The ICP system is much apart from LTE conditions. Thus, ethanol solutions will place a reducing effect on spectral line intensity.