Silicene , as the counterpart of graphene for silicon , with slightly buckled honeycomb geometry has been synthesized through epitaxial growth . This novel two dimensional material has attracted considerable attention both theoretically and experimentally recently , due to exotic electronic structure and promising applications in nanoelectronics as well as compatibility with current silicon-based electronic technology . In recent years semiconductor nanostructures have been converted to the model systems for investigation of electrical conduction on short length scales . The theorical framework commonly used to describe traort through nanoscopic devices is the Landauer-Buttiker formalism . In this approach current through a conductor is expressed in terms of the possibility that an electron can transmit through it . To simplify the discussion , we assume that the temperature is set to zero and traort is phase coherent . We consider a zigzag silicene nanoribbon divided into three regio the device region , the left and right lead , that local structural disorders and edge defects can affect the electronic traort properties of this nanoribbons . Additionally , the buckled structure of silicene enables us to apply external electric field and as a result can control bad gap in a wide range of energy in silicene . In this project , we provid systematic investigation on the electron traort properties of silicene nanoribbons in the presence of an external electric field , edge defects like vacancies and disorders (Anderson disorder) . We use the tight-binding model to describe the hamiltony of silicene system . Then introduce the concept of Green?s function and then show that a conductor connected to infinite leads can be replaced by a finite conductor with the effect of the leads incorporated through a "self-energy" fuction . This provides a convenient method for evaluating the Green’s fuctionn (and henece the transmission function) numerically . A numerical technique , for calculating the transmission coefficients through a coherent mesoscopic conductor using it’s Green’s function is introduced . Furthermore , we study the influence of the electric field on the band structure , total and local density of states in silicene nanoribbons . The results show jumps or steps in the conductance of zigzag silicene nanoribbons versus energy . The band structure obtained in this nanoribbons fully correspond to the diagrams of electrical conductivity . We show that the band structure can be controlled by applying an electric field perpendicular to the silicene sheet . In particular , the gap decreases linearly to zero at a certain critical electric field and then increases linearly . Moreover , the results show that disorders like , vacancies and disorder that is modeled with Anderson model lead to lower conductivity in zigzag silicene nanoribbons . The edge states of the zigzag silicene nanoribbons are resistant to the disorders , and in fact , this disorder has no effect on the conductance of the nanoribbons around the Fermi energy.