The plasma free amino acids (PFAA) were measured in 37 healthy children (27 boys

14 girls) under 4 years of age. Blood samples were drawn after an overnight fast. All the analyses were performed by elution chromatograph with a Beckman 121 MB Amino Acid Analyser. Data of plasma concentrations of 21 free amino acids and of 9 essential ones were collected. Among them

the concentrations of Alamine

Glutamine and Glutamate were on the top accounting about 40% of the total. In this study there revealed noither sex nor age differences in infants and children under 4 years of age

suggesting that in younger children the pool of amino acids is so expansible to fit their growth and development. The ratios of different amino acids were calculated. For example

NEAA/EAA was 1.5

Ala/Thr 2-3.0

Ala/Leu 2-2.5

Ala/ BCAA 0.6-0.7

Phen/Tyr 1 and Gly/Val 1. It seemed possible using these ratios to evaluate the status of malnutrition of young children