Abstract: To study the interactions of combining ability with environment for the stem characters in wheat, a set of diallel cross involving 7 random parents was made in three years. The resul showed that interactions of general combining ability with environment of top 1st and 2nd and basal 1st and 2nd internode length and top 1st internode stem diameter and interactions of special combining ability with environment of all internode length and basal internode stem diameter were significant. Top internode length and top 1st and 2nd and basal 1st and 2nd internode stem diameter mainly controlled by additive gene effect. Environment effect was highest and additive gene effect was second for basal internode length and middle internode stem diameter. Stability were higher for general combining ability and stability were lower for special combining ability .