Abstract:The study aimed to explore the effect of interaction between rhizosphere soil humidity and canopymicroclimate on photosynthesis in grape under drought stress. The changes of rhizosphere soil humidity, canopymicroclimate factors, photosynthetic parameters of deepfurrow planting and flatfurrow planting were studied under drought stress in field with rain shelter, using twoyearold seedlings ‘Jingya’ and ‘Red globe’ as testing materials. The results showed: (1) under drought stress, the rhizosphere soil humidity and canopymicroclimate interacted, and they effected photosynthesis by affecting water condition in grapes. The soil moisture threshold was the most effective soil moisture point for water utilization in photosynthesis of grape, and showed a “threshold drift” phenomenon. There was a significant negative correlation between the soil moisture and canopy air humidity. Therefore, higher canopy air humidity was beneficial to achieve higher photosynthetic efficiency under lower rhizosphere soil humidity condition. (2) Under drought stress, compared with flatfurrow planting, deepfurrow planting had obvious advantages to improve rhizosphere soil humidity and canopymicroclimate. Grape had stronger waterretaining capacity and higher water utilization efficiency under deepfurrow planting, thus had stronger photosynthetic efficiency. (3) Under deepfurrow planting, it was suggested: the rhizosphere soil relative water content of 30%-50% was the scope that significantly affected photosynthesis in grapevines; the appropriate soil moisture range for ‘Jingya’ and ‘Red Globe’ were 43.32%-50% and 40.19%-50%, respectively. The rhizosphere soil relative water content of 43.43% and 40.19% were the most effective soil moisture that generated the highest water utilization efficiency during photosynthesis in the leaves of ‘Jingya’ and ‘Red Globe’, respectively.