The changes of sea surface temperature (SST) was discussed based on the carbon and oxygen stable isotope data from total 83 samples of the Dawan Formation at Yichang Huanghuachang section and Chenjiahe section, 2 samples of the Honghuayuan Formation at Chenjiahe section. The impaction of SST on the distribution of graptolite fauna was consequently analyzed based on the study of graptolite sequence of Dawan Formation at Huanghuachang section and the data of the distribution of graptolite fauna on South China. It is concluded that the changes of SST is only an indirect factor for the distribution of graptolite fauna; the former theory of latitudinal zonation need to be prove by further more study.