The effect of applying synchronous nutrient fertilizer in tobacco cultivation under rainy weather conditions in southern China was explored in order to provide a theoretical basis for tobacco synchronous nutrient fertilizer to replace conventional chemical fertilizers.In two natural villages in Chenzhou，Hunan，a demonstration experiment was carried out to compare the efficiency of two main flue-cured tobacco varieties(Yunyan 87 and K326)with synchronous nutrient fertilizer and conventional fertilizer.Two treatments were set up，namely the synchronous nutrient fertilizer to lose weight by 25%(SNF25)and customary fertilization(that is，conventional fertilizer application without reduction，CF).By observing the growth of tobacco and measuring tobacco agronomic characteristics，yield and its constituent factors，and the nitrogen and potassium nutrient contents of tobacco leaves，the application effect of the synchronous nutrient fertilizer of tobacco was evaluated.The result showed that:Compared with CF，SNF25 did not affect the growth of tobacco and the leaf color of the middle and lower leaves，but the SPAD value was significantly increased.Among them，the SPAD value of the upper，middle and lower leaves of Yunyan 87 increased by 6.14%，10.14% and 18.86%，while these values of K326 increased by 6.88%，11.63% and 15.93%，respectively.In addition，SNF25 did not affect the agronomic traits of Yunyan 87 and K326. Among them，the plant height，number of leaves，stem diameter and leaf area were not significantly different compared to CF.Compared with CF，SNF25 Yunyan87 and K326 had no significant difference in fresh leaf yield and dry leaf yield per unit area.SNF25 and CF showed the same reqularity in leaf fresh weight and dry weight per plant.The fresh weight and dry weight of the middle leaf were the highest，followed by the upper leaf and the lower leaf.At the same time，there was no statistical difference in the fresh weight and dry weight of the upper，middle and lower leaves of the two treatments.The nitrogen and potassium contents of upper，middle and lower leaves in Yunyan 87 and K326 obtained from SNF25 were not significantly different from CF，that is，SNF25 could maintain the upper，middle and lower flue-cured tobacco nitrogen and potassium content levels.SNF25 did not affect the growth and agronomic characteristics of flue-cured tobacco.SNF25 could maintain the yield and nutrient level of flue-cured tobacco，and ensure the quality of flue-cured tobacco.