Chemoresistive carbon black-polyvinylpyrrolidone (CB-PVP) composite sensors were prepared with different physical properties in CB dispersion, CB content and film thickness by using the fabrication method of a drop casting or a spin coating. To verify the influences of the physical properties, their vapor detection characteristics were measured and evaluated in terms of the magnitude in sensor responses. From these evaluations, the highest response was observed around at the optimized CB contents of 12.5 wt.% for the drop casting and 17.5 wt.% for the spin coating. Furthermore, homogeneous CB dispersion and careful thickness regulation were found to be necessary to achieve a sensor with good performance. (C) 2009 Elsevier B.V. All rights reserved.