A field trial was conducted in red paddy soil to study effects of K application rate and ratio of basal and sidedressings(BS ratio) of the K fertilizer on growth,yield and quality of flue-cured tobacco.Results showed that when the BS ratios were the same K,the yield and production value were the highest with the treatment applied with 270 kg/hm² K (K₂O) in total,and the lowest with the treatment applied with 315 kg/hm²;with the rising of K application rate,the contents of total N and nicotine markedly decreased (r=-0.99^***,r=-0.97^***,P<0.001).When the K application rates were kept the same,the highest yield of tobacco leaves was obtained in the treatment being 3:7 in BS ratio and the lowest in the treatment being 5:5 in BS ratio.In terms of yield of tobacco leaves,the treatments of BS ratio were in the order of 70% > 30% > 50%,while in terms of proportion of top grade leaves,average price,production value and K content of tobacco leaves were in the order of 70% > 50% > 30%.Therefore,in soils,130 mg/kg 1 in available K content,keeping a feasible K application rate and increasing the proportion of sidedressing may improve use efficiency of the K fertilizer applied,K content and quality of tobacco leaves as well.In this experiment,the best combination is 270 kg/hm² in K application rate and 3:7 in BS ratio.