Abstract: In order to provide forecast of Osmanthus flowering period, the author used nearly 15 years of flowering observation data in Guilin, the forecast model was established by selected meteorological factors. The results showed that: the temperature, humidity, sunlight and rainfall had obvious effects on Osmanthus flowering. The influence cause of Osmanthus flowering was more complex. In the actual work of flowering forecast, according to the length of time in advance before flower, it could be divided into long-term forecast and short-term forecast. Long-term forecast was climate prediction, just a trend prediction of flowering late or early. Short-term forecasting was a forecast that make at 1 week before the flowering. Long-term forecasting and short-term forecasting model had achieved good effect in application in 2013.