In order to improve the genetic potentiality of potassium (K) uptake and utilization in sweet maize varieties, the genotypic differences of K accumulation and distribution of 22 sweet maize varieties were studied under same climate and soil with same fertilizer level. The results showed that K accumulation at different stages were different among different varieties. The mean of K accumulation percentage at the seedling-jointing stage, jointing-silking stage and silking-fresh stage was 10.0%, 73.6%, 16.4%, and with the range of 5.6%–19.8%, 48.0%–88.8%, 0.9%–42.1%, respectively. At the jointing stage, K was mainly in the leaf and sheath. After the jointing stage, the percentage of K in stem increased and reached maximum at the silking stage, viz. 39.9%, and kept stable in the following stage. At the fresh stage, the percentages of K in the stem, leaf and kernel were 39.5%, 22.0% and 10.4%, respectively. The varieties that had high fresh ear and grain yield had higher K accumulation amount at the jointing-silking stage and lower K distribution percentage in bract at the fresh stage. Among the 22 test varieties, 7 varieties (JSW etc.) had higher fresh ear and grain yield, higher K accumulation amount and higher distribution percentage in the grain at the fresh stage than those in the other 15 varieties.