The objective of the present study is to build a chemical sensor utilizing the feature of a high frequency SAW device for enhansing the sensor sensitivity and the feasibility of making a multi-channel structure on the substrate for integration of plural sensors. We developed the fine casting method (which was named as "droplet - surface casting method"), and deposited several kinds of adsorption films on the channels of a SAW device. The device was ST cut Quartz 90MHz SAW resonator chips, each of which has 2 resonators on a substrate. We constructed 4-channel odor sensing system that have one reference channel and three sensing channels using the two chips, and measured the response patterns of the organic solvents which have same carbon number and different atomic groups.