The age of eleven Sancai samples of Luoyang Tang Dynasty, Republic of China and modem age has been determined by pre-dose method and fine - grain mineral mixture technique method. Their result has been compared. By using pre-dose technique, comparatively better result in dating the 11 Sancai samples were obtained. Among the 11 samples, the measured age of 5 Tang Dynasty samples fell into the age scope of Tang; the measured age of 5 modem imitation samples was several decades B.P. ; the measured age of and imitation of Tang Sancai produced in Republic of China is 114 B.P. The above 11 Sancai samples of Luoyang Tang Dynasty were also measured by fine-grain mineral mixture technique. However, only the age of one sample among 5 Tang Dynasty samples fell into Tang Dynasty age scope; the measured age of 5 modem imitations fell into the scope of last twenty years, showing good result. The measured age of the imitation of Tang Dynasty Luoyang Sancai produced in 1996 fell into last several dozens of years scope; the age of the one produced during Republic of China was 882 B.P., which is obviously wrong. Hence, choosing which appropriate thermoluminescence method to determine the age of Luoyang Tang Dynasty Sancai samples is extraordinary important.