Based on the irrigation experiment of winter wheat in different water treatments, the paper analyzed the daily variation rule of stomatal conductance,canopy-air temperature difference, photosynthetic rate etc physiological indicators of winter wheat in heading stage under 5conditions of soil moisture, and carried out the correlation analysis between physiological indicators. The result indicated that the change of soil moisture has significant effect to physiological indexes such as tomatal conductance,canopy-air temperature difference and photosynthetic rate of winter wheat in heading stage, and the daily variation trend of each index is almost synchronous. Stomatal conductance appears active correlation with canopy-air temperature difference and photosynthesis rate. The canopy-air temperature difference and photosynthesis speed rise with the increase of stomatal conductance of winter wheat at heading stage. But the amplitude is different under different moisture conditions.