This paper studied methods for measuring soil available potassium(K)in order to provide scientific evidence for the reasonable application of K fertilizers to aid the cultivation of vegetables in the Chongqing suburbs.Seven methods(NH4OAc，ASI，Mehlich 3，HNO3，NaBPh4-1，NaBPh4-2，and boiling HNO3)were used to measure the content of soil available K，utilizing the yields and plant K uptakes of 36 K fertilizer field experiments conducted on lettuce as reference.It was found that the seven methods varied in extraction capacity and displayed an order of boiling HNO3＞NaBPh4-2＞NaBPh4-1＞HNO3＞Mehlich3＞NH4OAc＞ASI.The contents of soil available K measured with different methods showed positive correlation in different degrees，while all seven methods had the potential to evaluate the availability of soil K.The relative yield and relative plant K uptake were significantly correlated with the content of soil available K measured with the methods of NaBPh4-1 and NaBPh4-2，and the soil K measured with NaBPh4 was higher in bioavailability.Summarization of results showed that，in this study，the methods of NaBPh4-1 and NaBPh4-2 were superior in evaluating seasonal Kavailability of vegetable soil，with NaBPh4-1 being the best.