In this study, lettuces were treated with different concentrations ascorbic acid calcium (1,3, and 5mg/L). Effects of ascorbic acid calcium on the absorption of mineral matters, vitamin C contents, and nitrite contents were investigated. The results showed that ascorbic acid calcium significantly increased vitamin C content of lettuce leaves during the initial stage. With the extension of processing time, contents of soluble protein, chlorophyll, and nitrate steadily increased. Spraying ascorbic acid calcium increased leaf number, leaf area, and plant moisture content, and affected plant mineral elements absorption. With the increasing concentration of ascorbic acid calcium, the potassium and calcium contents of lettuce edible parts increased while the nitrogen and zinc contents gradually declined. After harvest, vitamin C and nitrite contents grew slowly with the ascorbic acid calcium treatment. Ascorbic acid calcium spray could increase the calcium and some microelements contents of lettuces to increase its nutritional quality and prolong the shelf life.