In this paper,some yellow synthetic diamond samples have been collected and tested by infrared spectroscopy and Raman spectroscopy.The diamonds are overviewed in several fields,which include the deposit,synthesis and gemology characteristics.In particular,the causes of synthetic diamond colors are investigated.The coloration of diamond is very complicated,which related to the impurities,color centers and defects in diamond.Base on the above studies,the following conclusions can be drawn.First,because nitrogen is the dominant impurity in most synthetic diamonds,structural nitrogen is the main cause of color in synthetic diamond and of great significance in the study of diamond coloration.Second,the fundamental theory can account for the coloration.