Abstract: Based on daily precipitation data between May and June during 1960-2016, early rice yield data during 1983-2016 in the whole province and municipalities, and disaster data during 1994-2016 in Guangdong province, this paper presents a design method of weather-based claiming index for early rice "Dragon Boat Rain" disaster insurance. Firstly, statistical method is used to establish the relationships between early rice yield and the total precipitation, rainfall anomalous percentage and rainstorm days during the "dragon boat rain" period of 21 May to 20 June in Guangdong. Secondly, using the case studies, the assessment model is established for effect of "Dragon Boat Rain" disaster on early rice yield, and tests are conducted for the reduction rate of per unit early rice yield affected severely by "dragon boat rain" in 2008 with the assessment model. It is found that its accuracy exceeds 75%. Lastly, the thresholds of early rice "Dragon Boat Rain" disaster insurance are determined to be the rainstorm days greater than or equal to 1 d, and the rainfall anomalous percentage greater than or equal to 20% during "dragon boat rain" period. Weather-based claiming index for early rice "dragon boat rain" disaster insurance are accordingly designed.