In the case of polymer composite filled with carbon nanotubes (CNTs), electrical conductivity can be theoretically obtained at content lower than 1 wt. % [1]. This percolated network can be used in industrial applications as protection from electrostatic discharge. Hence, CNTs filled materials can advantageously replace polymer-carbon black composites which contain usually around 20 wt. % of fillers. However, during forming process, the structure created by CNTs connections is strongly modified by the applied stress often resulting in an insulating final product. To understand the network evolution during process (for example extrusion), a rotational rheometer was used while the conductivity of the sample was monitored. This set-up allowed the observation of both destruction and establishment of CNTs connections during the shear. Under specific conditions, a dynamic equilibrium reports on comparable strength of these mechanisms. The structuration kinetics of the system under shear and in the quiescent melt has been studied to determine key parameters for the conducting network modification. Moreover, in case of semi-crystalline polymer, the percolated network may be disrupted or at least modified, during the cooling. Thus, the effect of crystallization has been followed showing a strong correlation between the conductivity obtained in solid state and this previously measured in the melt state. Consequently, the final conductivity reflects the global thermo-mechanical history of the composite material. 1. Balberg, I., Binenbaum, N. & Wagner, N. “Percolation thresholds in the 3-dimensional sticks system,” Physical Review Letters, 1984, 52, 1465–1468.