The response properties of quartz crystal coated with stearic acid LB films to organic gases were investigated by measuring the shift of resonant frequency. Stearic acid was used as a sensing material and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. The effect of temperature on the quartz crystal coated with stearic acid LB films was also investigated by Scanning Maxwell-stress Microscopy(SMM). As a result, the sensitivity of the quartz crystal coated with LB films to organic gases is dependent on temperature, thickness of LB film and molecular weight of organic gas.