Abstract: The paper aims to ascertain the occurrence and damage of sugarcane ratoon stunting disease (RSD) in Yunnan, and provide the guidance for the application and extension of healthy, bacteria-free seedlings treated with hot water and control this disease scientifically and effectively. In 2012-2014, the occurrence and damage of RSD were investigated in the 18 cane-growing regions of Yunnan, and 1091 samples were collected for RSD detection by using a PCR technique. The results showed that 825 samples (75.6% out of 1091) were positive for the presence of RSD. In Yunnan, RSD was detected in all 18 cane-growing areas at the rates of 56.4%-88% and the infection rates of the 28 main cultivars were 51.2%-100%. Ten main cultivars including Yuetang 93-159, Yuetang 00-236, Guitang 11 and Ganzhe 18 were infected seriously, their RSD incidence rates were more than 90%. Moreover, the plant crop and ratoons from both irrigated and rainfed fields were infected with RSD. Thus, RSD had become a major disease that seriously restricts the development of the canesugar industry in Yunnan due to cane yield loss and a shortened ratoon period.