Abstract: Under the condition of Laboratory，we study the effects of water status and temperature on leaf growth of wheat and maize through the determination of leaf extension rate， _s and _L．The results shows with the increase of temperature．1eaf extension rate increases first．arrives at highest value at 27℃ and then decreases rapidly．Under different soil statuses．there are lineral correlations between leaf extension rate and water stress．The changes of soll stres and temperature bring out the changes of _p．and osmotic potential aimcauses the change of leaf extension rate．As the increase of _p，leaf extension rate increases and at the same time the co-effects of water stress and temperature on leaf extension rate of maize is biggest．