We have investigated the influence of elastic deformation on resistance of glass cover bismuth wires with diameters from 50 nm to 1 m, in the temperature range of 4,2 – 300 K. The samples were strictly cylindrical shape monocrystals with orientation along the axis 1011, that confirmed by X-Ray diffraction studies, the study of angular rotation diagrams of transverse magnetoresistance and Shubnikov de Haas oscillations. Particular attention was paid to compliance of elastic deformation conditions, that confirmed by reproducibility of deformation curves and Shubnikov de Haas oscillations at several cycles of elastic stretching deformation. It was found that the deformation resistance curves essentially depends on samples diameters d and temperature T. Nonmonotonic dependence of the resistance to deformation extension at 4,2 K in wires with d > 100 nm was interpreted in terms of electronic topological transitions, under which the carriers from one single electron ellipsoid L1, extended along the wire axis with less carriers mobilities flow in L2,3 electron ellipsoid with more mobile carriers, which was confirmed by measurements of the SdH oscillations [1]. In the region of d ˂ 100 nm, where was semimetal-semiconductor transition due to quantum size effect, and the temperature dependence of the resistance R(T) is the semiconductor type, there is a significant change of deformation resistance curves R(ξ) at 4,2 K (Fig.1, insert). Fig.1. Deformation curves R(ξ) Bi wires of different diameters at T=4,2 K. 1. d= 300 nm, 2. d= 110 nm, 3. d=80 nm. Insert: deformation dependences of resistance R(ξ) wire Bi (1), T=4,2 K, d=50 nm и (2) Bi0,025at%Te, d=200 nm. Scale for curve 2 is increased by 2 times. Deformation resistance curve reflects drop resistance ≈ on 30 %, with the formation of step at ξ=11,3 %. This type of deformation resistance curve R(ξ) is typical for Bi wires doped by Te (curve 2 in the insert on Fig.1), when there are no holes in the T and conductivity is determined only by L electrons. This fact confirms the semimetal-semiconductor transition due to quantum size effect in quantum Bi nanowires with diameter less then 100 nm.