Abstract: As one of nationʼs big producers of rapeseed(Brassica napus L.),timely and accurate yield forecasts has great significance to ensure national grain and oil security in Sichuan province.In order to determine the type of historically similar years,the rape yield data and daily meteorological data from 1983 to 2012 at 30 stations in Sichuan basin area,as well as growth period of 13 agricultural meteorological observatory data were used to set up a comprehensive diagnostic index which based on correlation coefficient and Euclidean distance.By analyzing the relationship between meteorological influence index of rape yield in forecast year and similar year in history,the dynamic prediction method of rape yield in Sichuan basin area was determined.The results showed that the average accuracy of dynamic trend prediction was equal or above 80%,and the average accuracy of basin integration was equal or above 70%.The average precision of dynamic quantitative prediction in each producing area of Sichuan basin was equal or over 89.37%,and the average precision of basin integration was equal or over 96.16%.The precision of dynamic quantitative prediction in each producing area of Sichuan basin was equal or over 89.11%,and the precision of basin integration was equal or over 95.84%.The forecast results indicate that the method has good performance of accuracy to apply and can be applied to actual service.

Key words: rape(Brassica napus L.), yield forecast, dynamic, meteorological impact index, Sichuan basin