It is necessary for starting voltage to him on high pressure discharge lamp. This starting voltage supply to high pressure sodium vapor lamp as electric discharge lamp, Electric field is producted in Electric discharge tube, So accelerative electron collide against vapour atom and second electron is generated, And rapidly the current flow to Electric discharge tube. This paper showed that the life cycle and exchanges time for all electric discharge lamp was different according to each manufactures, This paper is proposed the evaluating algorithm of exchanges time for high pressure sodium vapor lamp, used LabVIEW software package.