Abstract: To understand the effects of drought stress on programmed cell death in different parts of tobacco plants, using Zhongyan 100 (not drought-tolerant) and Nongda 202 (drought-tolerant) as materials, 2.5% PEG-6000 was used to simulate drought stress in analyzing phenotypic difference between plants with different drought tolerance. DNA Ladder method and TUNEL method were used to determine the time and degree of programmed cell death in different parts of tobacco plants. The results showed that: (1) Under drought stress, the biomass, root length and root diameter of Nongda202 and Zhongyan100 decreased compared with the control. The decrease range of Zhongyan100 was larger and the difference with the control was extremely significant. (2) On the third day of drought treatment, PCD had occurred in all parts of Zhongyan 100 plants, but the response of different parts to drought stress was different. The degree of PCD in leaves and lateral roots was similar, and the degree of PCD in root tip cells was significantly higher than that in leaves and lateral roots. (3) According to the localization observation, cells of the lateral root cortex and cells far away from the veins developed PCD earlier. (4) Tobacco plants with higher drought tolerance showed later occurrence of PCD and weaker degree of occurrence. In summary, the time and characteristics of PCD in cells of different parts of tobacco plants under drought stress are different, and the time of PCD in plants with different drought tolerance is also different.