Abstract: The paper aims to study the effect of water stress on some agronomic characters of wheat seedlings, and analyze the relationship between those characters and drought stress. The authors took hybrid F2:3 population as the material, which was formed by the hybridization of‘Qingmai 6’and‘Yannong 24’, the mixed major gene plus polygene inheritance model was used to investigate the inheritance of these agronomic characters. Under water stress and drought stress, root length and root fresh weight fitted the inheritance model of one additive-dominant major gene, and the optimal genetic models of stem fresh weight, stem dry weight, root dry weight, ratio of root fresh weight to stem fresh weight and ratio of root dry weight to stem dry weight were different . Under drought stress, the major gene heritability of stem fresh weight was 37%, stem dry weight, root length, root fresh weight, root dry weight, ratio of root fresh weight to stem fresh weight and ratio of root dry weight to stem dry weight were controlled by the major gene, the major gene heritability of these characters was 51%, 81%, 74%, 56%, 50% and 68%, respectively. Although main genes were detected for stem fresh weight, stem dry weight and root dry weight, the genetic models were greatly influenced by environment and the genetic law of these characters should be further studied.