This study investigated the effect of exhaust hood during cooking case-study dishes of Eight Cuisines of China. Parameters were measured of hood idle or working mode included the continuous measurements of air temperature, air relative humidity and generations of CO, CO2 and TVOC of the breathing zone. Different from former researchers, we found the cooking techniques are not the reason that causes serious pollution. The emissions of CO and CO2 not only were related to the cooking time, but also occurred largely as a result of the burning of the gas; however, the generation of TVOC attributed in large part to using the seasonings, ingredients and the behavior of marinating. The maximum increase of TVOC concentration during cooking dishes with cooking wine was at least 526.7-543% higher than the others. Besides, the behavior of marinating would cause at least 80-556.3% increase. Compared to hood idle mode, the decrement of maximum increases of temperature, CO2 and TVOC concentrations were 7-50.29%, 6.6-379.5% and 136.6-4211.6% respectively in hood working mode. The situation became very complicated for relative humidity and CO concentration. Even with an exhaust hood, there was still a significant high value of contaminant levels in the breathing zone, especially in the beginning phase of the cooking process (200s). The values of test parameters finally reached a stable value after a certain period of time. This time of hood idle mode was almost the double of the hood working mode. (C) 2013 Elsevier B.V. All rights reserved.