Blood samples were collected from wing vein of 110 Japanese quails according to their age (< 1, 3 , 5, and> 5 weeks) and sex. Age had a significant effect on the concentrations of total protein, albumin, cholesterol and inorganic phosphorus (P < 0.05) as with the increase in age, there was an increase concentration in total protein and cholesterol and a decrease in albumin and inorganic phosphorus. There was no significant difference in any of the serum biochemical parameters of male and female quail’s blood.