Abstract: Two types of Cerasus humilis fruits screened for high and low calcium in Inner Mongolia area were used as test material, and the differences and variations of calcium content and pectin solubility of different forms in fruits of Cerasus humilis at different growth stages were analyzed and compared by step extraction and water, salt and alkali solution extraction, and correlation analysis was also carried out, in order to provide reference for the mechanism of calcitonin accumulation and the screening of high-calcium varieties of Mengyuan Cerasus humilis varieties.The results showed that the total calcium, effective calcium, pectin calcium, calcium phosphate and calcium oxalate contents of both types of Cerasus humilis fruits showed an increasing and then decreasing trend, and they were all the highest at the hardcore stage; the water-soluble calcium contents decreased and then increased slowly; and the residual calcium contents continued to decrease.The pectin content of each type of pectin in both types of pome fruits showed an increasing and then decreasing trend; total pectin and alkali-soluble pectin content were the highest during the coloring and expansion period,water-soluble pectin content was the highest during the hard ripening period,and salt-soluble pectin content was the highest during the sclerotization period.In terms of calcium nutrient content,both types of fruits had the highest total calcium content,followed by effective calcium content,pectin calcium and water-soluble calcium content were significantly higher than calcium phosphate and oxalate content,and residual calcium content was very low.Calcium and pectin correlation analysis showed that the calcium content of each type was positively correlated with total pectin,salt-soluble pectin and alkali-soluble pectin content,and less so with water-soluble pectin.