Abstract: On the basis of a systematical clarification for the temperature data of Guangzhou, Shantou and Macao before the Liberation in 1949, this paper established the sequences of temperature variation during the past 100 years for the above three sites and analyzed the temperature changing features of the southeast coastal area near Guangdong province over the past century. The annual average temperature has respectively risen up to 0.61℃,0.62℃,0.43℃ in Guangzhou, Shantou and Macao during the past 100 years, the increasing range is within the global average scope; The hugest increasing range of temperature in Guangdong province takes place in Spring, and secondly in Winter, which is different from other cities in China, that is, rising of temperature in Winter; the temperature rise in Guangzhou, Shantou and Macao is jointly on account of the changing order from the highest to the lowest, the highest and the lowest; moreover, there are universally about three circles respectively of 20 years, 12 years and 5 years existing in the above three sites.