Characteristic of Infantile Body Fluid balance B. Electrolyte composition of body fluid ECF:Na、cr,Hco3 ICF:K+、Mg2+、HPO42、 Protein C. Water metabolism a. Large water requirements, swift water exchange unobvious water loss(double adults amount ). Infants water exchange amount is 1/2 of ecf, the adult's is Just 1/7 b. Immature body liquid regulating function, immature concentration and dilution function of infantileCharacteristic of Infantile Body Fluid Balance B. Electrolyte composition of body fluid ECF: Na+ 、 Cl-，HCO3 - ICF: K + 、Mg 2+ 、HPO4 2-、Protein C. Water metabolism a. Large water requirements, swift water exchange, unobvious water loss (double adult’s amount ). Infant’s water exchange amount is 1 / 2 of ECF , the adult’s is just 1 / 7. b. Immature body liquid regulating function , immature concentration and dilution function of infantile