In order to investigate the factors influencing the determination of total volatile components in tobacco flavor, 6 tobacco flavor samples including top flavors and casings were measured in 4 laboratories. The factors involved were specifications of evaporating dish, boiling state and water level in water bath, and ventilation condition. The results showed that the specifications of evaporating dish affected test results obviously, while boiling state, water level and ventilation condition did not. Test results’ repeatability and reproducibility of transparent, homogeneous and highly volatile top flavors were less susceptible to test conditions, comparing with viscous and inhomogeneous low volatile casings. The conclusion is that the property of flavor sample, instrument and test operation all affected the test results of total volatile components though at different extent.