After Nitrogen, POTASSIUM is an essential and most consumed element, in plant’s growth. POTASSIUM has very important functions to regulation the osmotic potential of the cell, amass retention, the development of cells and stomata activity. Sugarcane (Saccharum officinarum L.), as an important product for the supply sugar and side industries, due to the high biomass need to attract a large amount of POTASSIUM during its life cycle. This research was done as a complete randomized block design, in applied research farm of Amir-Kabir Agro-industry. To do research, treatment of POTASSIUM NITRATE fertilizer was applied at three levels, control, 75 and 150 kg/h POTASSIUM. During the implementation of the research the density, yield, weight of stem, amount of available, fixed POTASSIUM and anatomical structure of plant aerial part were studied. Applying POTASSIUM fertilizer on treatment did not show significant changes on density and yield of the plant in the farm. As well as the amount of fixed POTASSIUM under the influence of POTASSIUM fertilizer treatment did not show significant changes, but in treatment 150 kg/ha, a significant difference in the amount of available POTASSIUM was seen. The amount of the stem weight in the treatment of 150 kg/ha POTASSIUM in compared to control and treatment of 75 kg/ha POTASSIUM showed significant difference. Often anatomical characteristics showed significant changes in sugarcane under the POTASSIUM treatment. The consumption of POTASSIUM fertilizer at the time of use didn’t developed growing conditions of sugarcane. Anatomical changes of aerial organs under the POTASSIUM fertilizer consumption represented the anatomical adaptation of plant to increase the soil POTASSIUM.