An electrical circuit model of the fluorescent lamp for high-frequency operation is presented. The circuit model is represented by a power and temperature dependent resistance. A test system is set up to obtain the lamp arc voltage equation for a given lamp from few test data, and then the arc current and the equivalent resistance can be derived. By these lamp equations, the electrical behavior of the lamp can be described. The circuit model can be used for predicting the operating characteristics of the dimmable electronic ballast-lamp circuits with considerations on the effects of the operating power and temperature. The verification of the proposed lamp model is illustrated by implementation examples.