Abstract
Today, energy conservation and environmental protection are important issues. As a light unit, LED can behave great in both issues. In the development process of LEDs, temperature is always an important subject. This study the relationship between ambient temperature and optical properties of LEDs. We go through the changes of Luminous flux、Radiant flux、Correlated color temperature、Dominant wavelength、Purity、Color rendering index in 25℃、35℃、45℃、55℃、65℃ respectively. To do the study in a setting environment, we construct a coated heating coil devices. This system can control ambient temperature by integrate sphere we design. We also develop program by Visual Basic. This program can get light source single that is trans by spectrometer, and calculate those single data to get these optical properties we want research. Finally we analysis these optical parameters by 「The relative initial rate」mathematic method, building the standard in manufacturing of LEDs in the future.