This Paper presents about selecting the most suitable load used for distribution optimization considering time-varying load demand and generation of DG. The objective of this paper is to find optimal load which obtain best network reconfiguration result according to time-varying load demand and DG generation. Many researches about distribution reconfiguration for optimization have been studied for ages and they have used constant loads only for reconfiguration. To get the best result, however, at least for 24 hours time-varying load demand and generation of DG should be considered. Four daily load curves and one PV generation curve have been decomposed into sequential levels. But, the optimal distribution reconfiguration considering time-varying load demand and PV generation should not to be the only scheme. Because, the reconfiguration result may demand hourly switching operation of electric devices and it might cause deterioration of switches lifespan. Therefore, the method of how to select the most optimal load considering not only time-varying loads demand and DGs generation but also the number of switching for maximizing income is researched. The method of selecting optimal load is proved by adapting to a simple model system and the more efficient result is also confirmed in this paper.