Guangdong green jade was found in Guangning County, western Guangdong Province. It belongs to altered sericite jade, with abundant colors such as green, white, yellow and black, with green being the main color. Transparency is an important parameter to evaluate the quality of a jade. Transparency of Guangdong green jade is generally low, mainly between the translucent and transparent type. A systematic experiment was designed for studying the factors controlling the transparency of Guangdong green jade. Based on the experimental results, it is suggested that the mineral structure of Guangdong green jade is crucial for the transparency. Impurities, cracks and colors also have some influence on transparency.