K⁺ channel is one of the important pathway for tobacco absorbing K⁺. In recent years, Many K⁺ channel genes have been cloned from various plants or different organization of same plant. In this paper, the type of K⁺ channel gene, cloning and function of K⁺ channel, K⁺ absorption mechanism and molecular regulation technology of K⁺ channel are summarized. Applying biotechnology to improve tobacco potassium nutrition character is discussed, and utilizing the modern biotechniques to improve the potassium content of tobacco leaves is proposed.