Paddy rice cultivars T-43 （drought-resistant type） and Xindao 1 （drought-sensitive type） were used to study rice yield and water use efficiency.Three irrigation modes including W1 （115.44 L/Pot），W2 （ 98.12 L/Pot） and W3 （83.41 L/Pot） were set to study the effects of drip volume on the morphology and distribution of rice root，the ratio of root to shoot，yield and water use efficiency at the stage of HS （heading stage） and 20 DAH （20 days after heading）. The results showed that the root length density （RLD），root surface area density （SAD），root mean diameter （AvgDiam） and root volume density （RVD） of T-43 at the stage of 20 d after heading under W1 treatment increased by 22.8% and 33.1%，21.8% and 37.7%，27.7% and 32.8% compared with other treatments，respectively. However，those indexes of Xindao 1increased by 80.2% and 53.2%，63.3% and 88.9%，95.0% and 32.3%. Under W2 treatment，the β value of RLD and SAD of T-43 varieties at the stage of heading increased by 0.4% and 1.7% compared with W1 treatments，the β value of Xindao 1 increased by 0.3% and 1.1%. Among them，0-40 cm RLD and specific root length （SRL） of T-43 increased by 1.2%-55.2%，1.6%-29%. Compared with other treatments，and 40-60 cm SAD，root dry weight （RDW） and AvgDiam of T-43 increased by 7.2%-13.8%，1.9%-3.0%，8.8%-9.4%. Thus，T-43 maintained a lower drip volume compared to W1 treatment. Under W2 treatment，there was no significant difference in yield and its components compared to W1，with a 4.5% increase in WUE. However，the yield and WUE of Xindao 1 decreased by 28.3% to 79.83 and 15.2% to 71.7% with the decrease of drip water. The results of correlation analysis showed that there was a significant or extremely significant positive correlation between various morphological indexes of yield，yield components，and WUE of the 0-20 cm shallow root of rice，greater than that of the 20-60 cm deep root of rice. It is indicated that there is a close correlation between morphological indexes of root and the yield，WUE of rice. It is feasible to regulate the distribution of shallow roots in crops and promote root development at the stage of 20 days after heading by appropriately reducing the amount of dripping water （about 15%）. The water use efficiency is improved without significantly affecting yield. Reasonable irrigation systems should be formulated based on the different water response characteristics of rice varieties in production to achieve higher economic benefits.