In this study, we examined whether organic iron can replace the inorganic calcium. We investigated the quality characteristics of egg produced from laying hens with non-supplemented diets or diets supplemented with organic iron on chitosan oligosaccharide. We are made of organic-iron on substrate of chitosan oligosaccharide. Organic iron or non-organic iron were mixed normal laying hen diet. Laying hens were fed diet for 45 days containing powdered chitosan oligosaccharide-Fe, Inorganic iron or normal feedstuff. Through the whole period of experiment, organic iron group increased the egg shell thickness and egg heights (yolk and albumen) compared to normal or inorganic iron (p<0.05). And, egg weights, edible weight and yolk colors were no significant difference. But, each effectiveness are different from organic-iron concentration to feeding period. Overall, It was investigated that organic iron had equal or more effects compared with inorganic iron or normal diet. These results suggest that organic iron could be used as substitute for inorganic iron as well as the supplement of laying hens diets to produce functional eggs.