Abstract: National Institute of Metrology (NIM) has independently developed LED filament standard lamp. Temperature is the main factor affecting the measurement value of LED filament lamps, and the accurate measurement of the temperature coefficient is required to study and analyze the characteristics of LED filament lamps. This paper introduces the definition and measurement principle of LED temperature coefficient, as well as NIM’s facility to implement the measurement. Experimental measurements of LED filament lamps are performed to analyze the relationship between lamp voltage, total luminous flux value and reference point temperature. The linear expressions of the total luminous flux value versus the reference point temperature and the lamp voltage versus the reference point temperature are fitted using the least squares method, and the temperature coefficients of the luminosity value and the lamp voltage are calculated sequentially. The experimental data show that the developed LED filament lamp has a photometric temperature coefficient of 0.17%/°C and a voltage temperature coefficient of −0.025 V/°C.