China is the largest apple producer of the world，and the apple industry occupies an important position in the national economy.Physiological diseases of the fruit caused by calcium deficiency seriously affect the quality of the fruit and restrict the healthy development of the apple industry in China.At the fruitlet stage or fruit expansion stage，0.05% 44CaCl2 was applied to the surface of Tonami and Fuji fruits with a brush to explore the difference in absorption of calcium fertilizer between Tonami and Fuji apples.It was found that treatment with 44Ca at 0.05% had no significant effect on the longitudinal diameter，transverse diameter，fruit type index，volume，surface area，dry weight and fresh weight of Tonami and Fuji fruits.After fruit surface was treated with 44Ca，the content of 44Ca in the leaves of the bourse shoots where the fruit was treated was the highest，followed by the fruit，and the content of 44Ca in the bourse shoot was the lowest.In apple fruit，the 44Ca content was the highest in the peel and the lowest in the flesh.The 44Ca uptake efficiency of Fuji(68.86%)fruit was significantly higher than that of Tonami(62.46%)when the fruit surface was treated with 44Ca at the fruitlet stage.With the fruit growth，the retention rate of 44Ca in the fruit gradually was decreased.The absorption efficiency of 44Ca on fruit surface at fruit expansion stage was 55.92% and 60.34% for Tonami and Fuji apples，respectively.Compared with Tonami apple，the absorption efficiency of 44Ca in Fuji apple was 7.90%-10.25% higher in fruitlet stage and expansion stage.At fruitlet stage，44Ca content and total 44Ca content were positively correlated with volume and surface area of fruit，while at fruit expansion stage，44Ca content and total 44Ca content were negatively correlated with volume and surface area of fruit.