It has been well known that glycine conjugates metabolites of toluene or xylenes are excreted in the urine of workers using thinner. Glycine conjugates were measured in the urine of three painting workers who were working in the same shop. The urine was taken three workers working in the same shop at morning (Am. 8:00), at noon (Pm. 0:00), at afternoon (Pm. 5:00) three times in the day during two weeks. Concentration of urinary metabolites taken was higher at noon or in the afternoon than those taken at morning. Data indicated that the painting workers were exposed to organic solvents at noon or at afternoon. This phenomenon was recognized in all week days. From these results, the author's suggested that alkyl benzene was excreted relatively fast.