Abstract In this research work we investigated theoretically the impact of Ni-doped Bi superconductor. By making use of the Ginzburg-Landau phenomenological equation, we have demonstrated the temperature dependence of the upper critical magnetic field of superconducting Ni dopedBi 4 O 4 S by using the Ginzburg-Landau (GL) phenomenological equation. We found the direct relationship between the GL coherence length (ξ 3 ) and penetration depth (λ ) with temperature. From the GL equations and the results obtained for the GL coherence length, the expression for upper critical magnetic field (H GL ) is obtained for the Ni doped superconducting Bi 4 O 4 S . The result is plotted as a function of temperature. The graph shows the linear dependence of upper critical magnetic field (H 3 ) with temperature (T) and our finding is in agreement with experimental observations. Keywords C2 Ginzburg-Landau equation, upper critical magnetic field, critical temperature Ni-doped Bi 4 O 4 S superconductivity 3 C2 GL 4 O 4 S 3