Abstract: Based on the 2010-2011 experimental data of planting flue-cured tobacco in its representative production counties of Yunnan Province, Southwest China, the models of the tobacco plant physiological development period and growing degree days were established, and validated by the observation data from local agro-meteorological stations. The two models had good performance at pre-transplanting stage, and the errors of the estimated dates were smaller. After transplanting stage, the errors of the estimated dates were larger, because of the disturbances from farming activities such as transplanting and topping. The simulated values based on the tobacco plant physiological development period had a higher coincidence with the observed values, especially at the pretransplanting stage, with the errors of the estimated dates being smaller than two days. As affected by the photoperiod effect, the model of tobacco plant physiological development period fitted better in high latitude regions than in low latitude regions.