A field trial was undertaken to evaluate the effects of applying Ca(NO3)2 in soil before flower period on the contents of potassium，calcium，magnesium and quality of “tainung No1”mango.The results showed that:(1) Compare with the results of the control,applying calcium fertilizer could obviously increase the fruit sugar acid ratio because of the increase of content of soluble sugars and acidity reduced,and improve the vitamin C in the fruit,reduce the rotten fruit rate during storage.The highest yield occurred when 150 g/plant calcium was applicated,and the yield increased by 14.25% compared to the control.(2) By applying calcium fertilizer,the calcium content of pulp in fruit was significantly increased,the magnesium and potassium contents of peel,pulp and seed in fruit reduced.(3) The calcium contents of peel,pulp and seed in fruit had positive correlation with the calcium application amounts,and the potassium and magnesium contents of peel,pulp and seed in fruit had negative correlation with the calcium application amounts.(4) The contents of soluble sugars,vitamin C and sugar acid ratio were positive correlation with the calcium application amounts.The contents of soluble solid,acidity,weight loss ratio and the rotten fruit rate were negative correlation with the calcium application amounts.It suggested that applying Ca(NO3)2 in soil could increase quality and improve storability of mango during storage.