The assemblies (films) of carbon nanotubes (CNTs) possess very stable, repro ducible, and extraordinary electronic properties. These films have been considered as attractive materials for various nanosensors and as electrodes of electrochemical energy storage devices, like supercapacitors, with low equivalent series resistance and highly developed internal surface. In order to develop CNT devices operating at the room temperature, it was necessary to determine the assembled films' properties, such as the mechanism of conductivity, carrier concentration, and mobility. In this study, we are focused on the assemblies (monolayers, arrays, and films) of multiwall carbon nanotubes (MWCNT). We applied a wide temperature range resistance and magnetoresistance as a tool to determine the transport characteristics of MWCNT films. The measurements of the electrical transport (temperature dependence of the resistance) in the assemblies of nanotubes were tested in the temperature range T = 1.5-300 K, and the magnetoresistance measurements were carried out in pulsed magnetic fields up to 35 tesla in the temperature range 1.5-300 K. The mechanisms responsible for the transport in these systems, including weak localization, antilo calization, Luttinger liquid, Shubnikov-de Haas oscillations, and intertube coupling, were observed.Perspective of Carbon Nanotubes 2 the lowfrequency impedance of fibers composed of SWCNTs (at cryogenic tem peratures and a constant electric bias) [22,23]. Quantum transport properties have been observed both in singlewall (SWCNT) [5,9,[24][25][26][27][28][29] and multiwall nanotubes (MWCNT) [3,[30][31][32][33][34][35].Quantum interference effects, such as weak localization (WL), the Aharonov-Bohm (AB) effect, the Al'tshuler-Aronov-Spivak (AAS) effect, and universal conductance fluctuations (UCF), have previously been observed in multiwalled carbon nanotubes [32]. Knowledge of phasebreaking effects in coherent transport is very important for the study of these quantum interference phenomena. The temperature (T) dependence of the phase coherence length, Lφ, of MWCNTs has been reported to follow a power law dependence of T −1/3 , a characteristic of one dimensional interference [36]. In the case of singlewalled CNTs, the power law dependence also shows a T −1/3 dependence [28]. In addition, as further evidence of lowdimensional transport, there are some experimental reports of Tomonaga-Luttinger liquid behavior in CNTs [37].From one point of view, for the array (assemblies) of nanotube samples, the synergetic properties were expected only [38]. But, the transport in the arrays of nanotubes was found to show single nanotube properties at low temperatures due to the mostly conductive nanotubes responsible for the transport [25]. On the other hand, for specific new applications, like chemical [15,16] and bio [17][18][19][20][21] sensors, the synergetic properties of the arrays of nanotube samples are important [39]. They are based on their large surface area per volume and intertube coupling in electrical tra...