Abstract: In order to investigate the effects of cigarette smoke trapping on in vitro cytotoxicity test, 3 kinds of trapping systems, including Cambridge filter-pH7.0 PBS-acetone, Cambridge filter-pH7.2 PBS-ethyl acetate and Cambridge filter-pH7.4 PBS-70% glycerol, were used to collect particulate matter and gas phase from the mainstream smoke of the same cigarettes, the cytotoxicity of smoke trapped at each stage in the systems to CHO (Chinese Hamster ovary) cells was tested by neutral red method, and the chemical compositions in the matter trapped by organic solvents were analyzed by gas chromatography-mass spectrometry. The results indicated that: 1) the cytotoxicity of the matter trapped by Cambridge filter was more significant than that by PBS and organic solvent; 2) for the 2nd stage trapped matter, the cytotoxicity of that trapped by pH7.4 PBS was significantly higher than that by pH7.0 and pH7.2; 3) for the 3rd stage trapped matter, the cytotoxicity of that trapped by the 70% glycerol was significant, that by acetone and ethyl acetate was less and close. The vapor phase components trapped by the 3 organic solvents were mainly aldehydes, esters, alkanes and benzene analogues. There were more alkanes and benzene analogues captured by 70% glycerol. In conclusion, the smoke condensate trapped by Cambridge filter reflected part of neutral red cytotoxicity of smoke to CHO cell, while that trapped by Cambridge filter-pH7.4 PBS-70% glycerol more completely reflected the cytotoxicity of smoke.