Abstract:Using SDS-PAGE electrophoresis analytic method, a study on the change of drought-induced protein in leaves of alfalfa cultivars under different extents of drought stress was conducted. The result showed that there was a direct correlation between the change of drought-induced protein and drought stress intensity. As drought intensity increased gradually, the drought-induced protein increased initially. and then decreased. The amount of drought-induced protein varied among the different alfalfa cultivars. Those with strong drought-resistance could induce gene to produce more protein to adapt to the drought, while those lacking in drought-resistance would be weakened or lose self-adjustment. Thus, less drought-induced protein was produced. All the strong drought-resistance cultivars, after 15 days under drought stress, were induced to produce a new soluble protein pattern, while only CW300 and Archer Ⅱamong those weak in drought-resistance gave soluble protein pattern. All this indicates that the different cultivars possess distinct genetic diversities. Strong drought-resistance is an important property for breeding new cultivars.