Abstract: Two maize (zea mays) varieties with different drought resistance were us ed to study the differences between leaves and roots in osmotic adjustment under water stress condition. The results were the osmotic adjustment (OA) of leaves became greater as the soil water content decreased in jointing, big bell and he adi ng stage, but it was smaller in the milk stage. The OA of the drought resistant va riety Luyu No.14 was greater than that of Yedan No.13 which is a drought sensiti ve variety. The OA of leaves was greater than that of roots. The OA of roots was s mall from heading stage under serious stress condition, and even became smaller than slight water stress condition. The concentrations of4 different solvable m atters, solute sugar, free amino acid, proline and K+ were increased as the so il wa ter content decreased. The levels of these solvable matters were lower in roots than in leaves, which was consistent with OA. The solute suger contributed more to O A, K⁺ was the second in slight stress condition, but the percentage of free ami no acid and proline increased under serious stress condition.

Key words: Zea mays, Osmotic adjustment, Drought res istance, Water stress