Environmental monitoring by measuring the air, concentration of solvent mixtures should be the most useful method in the exposure assessment. But the solvent mixtures in air can be difficult to measure. In order to improve the method for air measurements of solvents, the author developed a simultaneous determination method for mixtures of 23 solvents using gaschromatography. And also for the purpose of assessing occupational exposure to solvent mixtures, the author applied this method to measure the air concentrations of solvent mixtures in industrial setting. The best condition of this method was 35degrees C-150degrees C for column temperature, 250degrees C for detector and injector temperature with capillary OV-1 column at 0.2 kg/cm2 if inlet pressure. And The recovery rates were 90% and over for 16 organic solvents including toluene and 70% and less for 4 organic solvents including ethanol. In raw materials (adhesives, diluents) of 3 industrial settings (paint manufacturing industry, chemical products industry & fishing products industry), the major components was aromatic hydrocarbons (toluene, o-, m-, p-xylene), and the number of detected items among 23 solvents were 4-16. The C(n)/N(n)-value (2.02) at one unit of adhesives developing department in chemical products industry exceeded permissible exposure limit (1), and C(n)/N(n)-values demonstrated a remarkable range (C(n)/N(n)-values were 0.04-2.02 for charcoal tube and 0.02-0.68 for passive sampler).