Abstract: Banana is a high potash-consuming crop. Potassium, nitrogen, calcium and magnesium are the four most vital nutrients for banana. And potassium, calcium and magnesium nutrient supplement one another. A field experiment was conducted to investigate the effects of potassium, calcium and magnesium application doses on banana plant growth, and fruit yield, quality and storage. The study shows that proper potassium, calcium and magnesium application doses promote banana growth, and enhance fruit yield and quality. And membrane lipid polyphenol oxidase activity and MDA content in peel, and amylase activity in pulp of banana fruit are debased under proper potassium, calcium and magnesium application doses. Various and simultaneous treatments also reduce weight loss during banana fruit storage, retarding ageing and increasing storability of banana fruit. To achieve high banana yield, quality and storability in Gaozhou City and the larger Guangdong Province, the simultaneous application of 990 kg·hm^-2 of K₂O, 37.5 kg·hm^-2 of Mg and 90.0 kg·hm^-2 of Ca are recommended.