A field experiment was carried out to study the effects of three chemical agents(including water-retaining agent

FA Handilong and mixture of CaCl2 and GA) on soil moisture content of plough player and water relation of winter wheat under different irrigational conditions at later growth stage in subhumid zone.The results showed that water-retaining agent and FA Handilong had better effects on increasing the soil moisture content of plough player

flag leaf water potential and leaf WUE

especially the water-retaining agent.In contrast to CK

the average value of soil moisture content and leaf water potential under water-retaining treatment after flower stage was increased by 9.7% and 10.8% individually under irrigating twice

while it was increased by 5.3% and 7.4% individually under no irrigation in the experiment.The mixture of CaCl2 and GA could significantly decrease rangeability of daily change of leaf water potential and WUE.By regression analysis

soil water potential determined the leaf water potential

meanwhile there was a positive correlation relationship between leaf water potential and leaf WUE.The results also showed that all these three chemical agents had different way to improve yield of winter wheat

but water was the critical factor on yield in this experiment.Under the same irrigational condition

there was no variance in yield or ears number among four treatments

but under the different irrigational conditions

the variance of yield was dramatic.