In this study, the effect of various mixture fluxes of nitrogen (N-2) and hydrogen (H-2) on carbon nanotube (CNT) synthesis grown on flexible carbon cloth using thermal chemical vapor deposition (thermal CVD) with ethylene (C2H4) as the carbon source and nickel (Ni) as the catalyst was investigated. Field emission scanning electron microscopy (FE-SEM) was utilized to study the morphology of CNTs on flexible carbon cloths with various N-2 and H-2 inlet flow rates. The results indicate that average diameter of MWCNTs decreases with increasing H-2 and N-2 flow rates; however, the density of CNTs increases first and then decreases with increasing H-2 and N-2 flow rates. On the other hand, in our field emission experiments, the result indicates that the field emission is strongly dependent on the density and geometry of MWCNTs. In addition, we also found that the contact electrical conductance measurement is an easy method to predict the field emission characteristics of MWCNTs. (C) 2012 Elsevier B.V. All rights reserved.