A method for the determination of total and available potassium in tobacco soil was developed by ion chromatography. Dionex RFIC CS12A separation column and CG12A protective column were used for separation and the mobile phase was 20 mmol/L methanesulfonic acid solution,the flow rate was 1.0 mL/min with suppressed conductivity detector,and the column temperature was 25 ℃ and the inject volume was 25 μL. The results showed that the calibration curve was linear in the range of 1.5~15 mg/L with a correlation coefficient(r)of 0.999 3,and the linear equation was y=5.634x-0252.8. The detection and quantification limit were 0.31 mg/kg and 101 mg/kg,respectively. The recovery of standard addition were from 98.31% to 101.3%，and the RSD(n=6)were from 0.5% to 3.9%. This method was credible,simple,fast,and suitable for the analysis of potassium in soil. The analytical results showed that sandy soil from Shaowu and loam soil from Pucheng had the highest potassium content,including total potassium and available potassium. These conclusions were helpful for potassium fertilizer application in tobacco soil.