Abstract: During eggs incubating, embryonated eggs grow continuously and a series of metabolism take place by enzymecatalyzing. Studies indicated that the content of healthful substances increased. For instance, the content of protein and amino acidincreased more than 1%, taurine increased 20 times, Calcium (Ca) increased 6 times, phosphorus (P) increased 8%, iron (Fe)increased 40%, VA increased 7 times, VB1 increased 3 times and VE increased 100 times, lysozyme increased 1 times and linoleicacid increased 1 time. The contents harmful to human’s health decreased as the fat dropped 50% and cholesterol dropped 5.5 times.It is important to nutrition improvement and prevention of disease in human health.

Key words: incubation, embryonated egg, nutrient substance, effective factors