[Objective]The study aimed to forecast the first flowering date of Osmanthus fragrans. [Method] Based on the data about flowering stage of O. fragrans in Guilin City from 1999-2012,the correlation between meteorological factors and the first flowering date of O. fragrans was analyzed,and a forecast model for the first flowering date of O. fragrans was established. [Result] Among meteorological factors,precipitation, humidity,temperature and sunshine hours could obviously affect the first flowering date of O. fragrans,especially humidity in August,temperature and sunshine hours in September. The forecast model could exactly forecast the first flowering date in the partial early or too late year,and the average error of date was 6 days. The factors influencing the first flowering date of O. fragrans are complex,and there is an artificial error in record data of the flowering stage,so using a single model to forecast the first flowering date have some disadvantages. When forecasting the first flowering date,we should consider all influencing factors to get a good forecast result. [Conclusion]The research could provide a new method to forecast the first flowering date of O. fragrans. [Objective] The study aimed to forecast the first flowering date of Osmanthus fragrans. [Method] Based on the data about flowering stage of O. fragrans in Guilin City from 1999-2012, the correlation between meteorological factors and the first flowering date of O fragrans was analyzed, and a forecast model for the first flowering date of O. fragrans was established. [Result] Among meteorological factors, precipitation, humidity, temperature and sunshine hours could obviously affect the first flowering date of O. fragrans, especially humidity in August, temperature and sunshine hours in September. The forecast model could exactly forecast the first flowering date in the partial early or too late year, and the average error of date was 6 days. The factors influencing the first flowering date of O. fragrans are complex, and there is an artificial error in record data of the flowering stage, so using a single model to forecast the first flowering date have some disadvantages. irst flowering date, we should consider all influencing factors to get a good forecast result. [Conclusion] The research could provide a new method to forecast the first flowering date of O. fragrans.