The objective of this study was to evaluate effects of nitrogen and potassium applied trough water irrigation on physiological characteristcs of banana cv Prata Anã in the coastal tablelands of Sergipe State. The experiment was carried out in the Sergipe Federal University Experiment Station, as 4x4 factorial, in randomized blocks with four repplications. Doses of nitrogen as ureia were (0; 250; 500 e 750 kg ha-1) and doses of potassium as potassium chloride were (0; 290; 580 e 870, in kg ha-1 of K2O). Vegetative growth, biomass partition and photosynthesis efficiency were determined. Plant aerial biomass of 8054.88 g plant-1 was achieved with the application of 700 kg ha-1 year -1 of N and 1200 kg ha-1 year-1 of K2O. Biomass distribution was: 16.515 to the leaves, 43.77 % to the stem and 39.71% to fruit brunches. Higher nitrogen and low potassium causes ontogeny, decreasing leaf area index and yield. Maximum solar irradiation conversion into biomass was observed at 732 kg ha-1 of N e 1200 kg ha-1 of K2O.