The distribution of double labeled P^(32) and Ca^(45) in the various tissues were investigated in fourty chicken. The results obtained were as follows: 1) The highest differences were observed in the thyroid gland between the sex in 24 hrs. after double administration of P^(32) and Ca^(45). 2) Generally, the distribution of double administrated P^(32) and Ca^(45) were higher in 24 hours than in one hour. 3) The sequence of the distribution of P^(32) and Ca^(45) in Various tissue were, thyroid gland, femur, adrenal, genital organs, pituitary, kidney, liver, spleen, brain, and G-muscle.