This paper describes the use of the pre-dose Thermoluminescence (TL) dating technique on eight ancient city wall brick samples from Shonghe Town, Hainan province. The sand content of the clay near this area is quite high due to its proximity to the sea. When using this clay to produce wall bricks during ancient times, the firing temperature is much higher than used for making wall bricks in other areas. Of the eight specimens of wall brick, 4 are gray, 3 are red and 1 is gray outside and red inside. When measuring the paleodose of brick samples by the method of High Temperature All Grains, it is found that the luminescence sensitivity of samples is very poor and irregular, so it is very hard to find the plateau area in the plateau curve and impossible to determine the correct ages of these ancient wall brick samples by this method. Afterwards, regression method of saturation exponential in predose technique is adopted to date these ancient brick samples. It is found that these samples have a good pre-dose Thermoluminescence effect and that the paleodose reproducibility of the samples is also good. Gray brick samples no. 2, 3, 6 and 8 are dated as A.D. 1423, A.D. 1439, A.D. 1484 and A.D. 1434, in the early Ming Dynasty (14th-15th century); red brick samples no. 1, 4 and 7 as A.D. 1604, A.D. 1669, A.D. 1639 in the late Ming Dynasty (16th-17th century) and no. 5 is dated as A.D. 1874 in the late Qing dynasty (19th century), respectively. The size and composition of sample no. 5 is very similar to those of samples no. 1, 4 and 7. It is inferred that is has been produced at about the same time as no. 1, 4 and 7, but that the TL dating age of sample 5 is much younger. According to a fieldwork investigation by archaeologists, there was an accidental fire in the late Qing Dynasty where sample no. 5 was unearthed, which is in agreement with the TL dating age of sample no. 5 sample.