An LED tube lamp includes a first rectifying circuit, a second rectifying circuit, an LED lighting module, a mode determination circuit and a mode switching circuit. The first rectifying circuit is coupled to a first pin and second pin and is configured to rectify an external driving signal transmitted from the first pin and/or the second pin. The second rectifying circuit is coupled to a third pin and a fourth pin and is configured to rectify the external driving signal with the first rectifying circuit. The filter circuit is coupled to the first rectifying circuit and configured to filter the rectified signal. The LED lighting module has a driving circuit and an LED module, and is coupled to the filter circuit and is connected to receive the filtered signal. The mode determination circuit is configured to generate a first determined result signal based on the external driving signal. The mode switching circuit is coupled to the filter circuit and the driving circuit, and is configured to determine whether to perform a first driving mode or a second driving mode based on the first determined result signal. The driving circuit receives a filtered signal from the filtering circuit and drives the LED module light when performing the first driving mode, and the filtered signal bypasses at least a component of the driving circuit to drive the LED module to light when performing the second driving model.