Generally, the appropriate alignment of CNTs facilitates CNT contacts to transport charge carrier in CNT oriented direction. Lanticse et al. [3] utilized the doctor blade technique to induce the alignment of CNTs, and indicated the electrical conductivities in CNT alignment direction are several orders of magnitude times higher than that of the composite with randomly dispersed CNTs, depending on the CNT contents. Oliva-Avilés et al. [5] also found that electrical conductivity is 3–5 orders of magnitude times higher for composites with electric field-aligned CNTs than that for randomly aligned composites. Compared to the results in the present study, it can be found that the variation of electrical resistivity is also several orders of magnitude when the random CNT distribution transforms aligned distribution. More attractively, we in situ record the variation of electrical resistivity during the transformation process of CNT distribution and study the influence of polymer matrix polarity on resistivity variation. Concerning the mechanism underlying the influence of EVA polarity on electric field-induced aligned CNT network can be understood through the schematics of their microstructural developments in electric field shown in Fig. 7. Fig. 7a shows the CNTs are in the random distribution and do not create conductive junctions, so their volume resistivity is very high. In the presence of electric field, CNTs experience a polarization, which leads to a torque NE acting on CNTs [10]. It has already been confirmed that the static polarizability in the direction of the tube axis is much larger than across the diameter for CNTs [24]. Under this condition, NE aligns CNT against the viscous drag of the surrounding EVA melt in the direction of electric field. Therefore, the aligned CNT network is revealed in Fig. 6b. Compared CNT behaviors in EVA10 and EVA25 melt, the stronger interaction between CNTs and VA segments and higher viscosity of EVA25 both limit CNT alignment in EVA 25 melt because EVA25 contains more VA segments than EVA10. This allows CNTs to be in a better alignment in EVA10 as shown in Fig. 6b. The variation of EVA polarity changes CNT–EVA interaction and affects CNT behaviors in electric field, which is in agreement with the variation of tp, Ea and Φ∗ values of the aligned CNT network formation.