In this study, a single bubble behavior in dielectric viscous fluid under the uniform magnetic field has been simulated numerically by using a level set method in two-phase bubbly flow. The two-phase bubbly flow considered to be laminar and homogenous. Deformation of the bubble was considered due to buoyancy and magnetic forces induced from the external applied magnetic field. A computer code was developed to solve the problem with flow field, interface of two-phases, and the magnetic field. The Finite Volume method was applied using SIMPLE algorithm to differentiate the governing equations. Using this algorithm enables us to calculate the pressure parameter which was eliminated by previous researchers due to complexity of the two-phase flow. The Finite Difference method was used to solve the magnetic field equation. The results outlined in the present study well agree with the existing experimental data and numerical results. The results show that the magnetic field affects and controls the shape, size, velocity and location of the bubble.