Abstract: An experiment was conducted to study the effects of applying calcium on the calcium content and quality of nectarine (prunus persica var. nectariana cv. Shuguang) under protected culture. The results showed that within a certain range of calcium level, with the increase of calcium application, the single fruit weight, yield, calcium content, content of soluble sugars, fruit firmness and content of Vc of nectarine fruit under protected culture were significantly increased. Both the application of Ca(NO3)2 and CaSO4 in soil reduced significantly the rate of core cracking. The lowest core cracking was found at Ca application of 200 g/plant for both Ca fertilizer being 36.1% and 38.3% for Ca(NO3)2 and CaSO4, respectively. Different Ca fertilizer had no different influence on the content of titratable acidity, which ranged between 0.43%-0.45%.