In order to compare the effect of both contaminant removal and ventilation inside the aircraft cabin under differentair supply modes considering the issue ofbleedingair contaminant transmission, an experimental measurement was performed in a cabin mockup which contains five rows of seats. The concentration diffusion of both instantaneous and continuous bleeding air contaminant were measured under air supply modes of ceiling and mixture type respectively insidethe cabin mockup, and the corresponding air qualities in the cabin were evaluated. The results of experiment indicated that bleeding air contaminant arrived earlier at the seat near the window of cabin than other places under the air supply mode of ceiling while arrivedearlier at the middle seat undermixture air supply. Mixture air supply is more likely toaccelerate the transmission of contaminant but with a lower concentration and a higher rate of contaminant removal. More effective ventilation and better air quality exist under the mixture air supply mode while the ventilation volume is equal.