The suitability of seven methods for chemical extraction of available potassium in the upland field was studied by using exhaustion pot experiment as the reference standard. The results were summarized as follows: 1.Available K absorbed by plants mainly Came from the nonexchangeable K, which was the main source of K takd up by plants. 2. Der termination results of correlation coefficients between four reference standards of pot experiment and results of seven chemical methods showde that correlation between cold 2 mol/L HNO₃ method and Cation-exchange resion bag method was highly significant (0.953 and 0.903 average). 3. The correlation between the nonexchangeable K extracted by cold 2 mol/L HNO₃ method and Cation-exchange resin bag method and the amount of nonexchangeable K absorbed by plant was highly singificant. 4. Both of the cold 2 mol/L HNO₃ method and Cation-exchange resin bag method could be recommended as the methods for the determination of available potassium in upland field, but the Cold 2 mol/L HNO₃ method was more simple and convenient than the Cation-exchange resin bag method.