Recently, energy saving technology for reduction of CO2 emissions has been developed. As one of these technologies, the high efficiency LED light bulb is focused. Production volume of LED light bulb has been growing rapidly. In order that LED light bulbs could be widely applied, grasp of characteristics in voltage dips using LED light bulbs is important. In this paper, characteristics of LED light bulbs were investigated by varying the voltage and duration in use in low voltage. Consequently, characteristics curves for LED light bulbs in voltage dips were obtained.