Abstract: This article represents the simulation model of switching over voltage in black start process by implementing Matlab/psb model and EMTP software separately. Comparing the EMTP with an analyzed simulation of a real system could prove the reliability of Matlab/psb result for an over voltage simulation, and Matlab/psb could be one of the powerful instrument for a power system simulation. Meanwhile it could be concluded that lightning protector would effectively reduce over voltage for several fold, and make switch close successful in early stage during black start.