[Objective] The water consumption and yield in the drip regulated deficit irrigation were studied by field experiment in order to provide a theoretical basis for the high yield planting of Isatis tinctoria in arid and semi-arid areas.[Methods] Water consumption and yield changes were analyzed by field trials.[Results] The water consumption in the vegetative growth period was gradually reduced with the increase of water deficit. Compared with the one of CK

water consumptions of regulated deficit irrigation reduced significantly by 4.11%~15.71%(p < 0.05). In an overall

the water consumption intensity basically showed its minimum in the seedling stage(about 0.90 mm/d). In the fleshy root maturity stage

it was larger(about 1.60 mm/d); and in the vegetative growth and fleshy root growth period

it got the largest(about 3.00 mm/d). There was no significant difference between the ones of WD4(mild water deficit during growth and fleshy root growth) treatment and CK(p > 0.05). The yield of Isatis tinctoria reached 8 235.32 kg/hm2. Treatment of WD1(mild water deficit during vegetative growth) had the highest water use efficiency 23.62 kg/(hm2·mm)

the one of WD4 was 6.74% and its was higher than the one of CK. Comparatively

WD4 was the best treatment.[Conclusion] Moderate water deficit had no significant yield difference with the one of CK

hence it can effectively reduce the water consumption of each growth period and correspondingly improve the water use efficiency. However

severe water deficit leads to a significant decrease in soil moisture

which is not conducive to the growth of Isatis tinctoria.