The observed inability of 6-d-old seedlings of spring wheat (Triticum aestivum L.) to tolerate the same water deficit as compared to the 4-d-old seedlings seems to be associated with the higher carboxypeptidase and lower aminopeptidase activities. Free amino acid pools differentiated also the 4-d-old seedlings from the older ones. Dehydration decreased the amino acid content in 4-d-old seedlings, increased it in 6-d-old seedlings and changed composition of amino acid pool. In tolerant phase of wheat seedling growth carboxypeptidase activity increased in response to water deficit and aminopeptidase activity increased in dehydrated seedlings, independently of their age.