57 rice varieties mainly planted in the middle and lower reaches of Yangtze River were used to study the physiological and biochemical characteristics of potassium efficient rice varieties planted in this region.Hydroponic culture was conducted to screen potassium utilization efficiency.The potassium efficient and potassium inefficient rice varieties were used to analyze the differences in growth，yield formation，absorption and translocation of potassium，the expression level of related genes with hydroponic culture，soil pot experiment，and field assay.The results showed that the potassium efficient and potassium inefficient rice variety was determined to be Xiangliangyou No.16（23#） and Xinganxiangzhan（14#）.The potassium efficient rice variety had better root architecture and biomass under both +K and -K treatments，with significantly higher plant height，root length，number of root tips，total surface area and volume of roots，and dry weight of roots and shoots compared to that of potassium inefficient rice variety.The effective number of spikes，spike length，thousand-grain weight，and grain yield of the potassium efficient rice variety was higher than that of the potassium inefficient rice variety.The absorption，translocation and utilization of potassium in potassium efficient rice variety was significantly higher than that in the potassium inefficient rice variety.The accumulation of potassium in roots and shoots，the absorption of potassium in plant，potassium utilization index，and distribution ratio in grains of potassium efficient rice variety were all significantly higher than that of the potassium inefficient variety.The expression level of OsAKT1，OsHAK1，OsHAK4，OsHKT2；1，OsKAT2，and OsKAT3 gene in the potassium efficient rice variety was significantly higher than that in the potassium inefficient rice variety.It is indicated that excellent root architecture，stronger absorption capacity of potassium，efficiently transporting potassium to shoot，and distributing more potassium to grains are important characteristics of the potassium efficient rice variety.