［Objective］The objective of this study was to investigate the transpiration responses of Populus simonii with different degradation degrees to meteorological factors in the Bashang area.［Methods］Populus simonii with different degradation degrees in Zhangbei County，Bashang area were taken as the research object. The sap flow of P. simonii with different degradation degrees（no degradation，light degradation，moderate degradation，and severe degradation）was monitored by the thermal dissipation sap flow probe. Meteorological factors such as photosynthetically active radiation，precipitation，wind speed，air temperature，vapor pressure deficit and relative humidity were simultaneously monitored. The transpiration characteristics of P. simonii with different degradation degrees and their relationship with meteorological factors were studied.［Results］1）The transpiration rate of P. simonii with different degradation degrees during the growing season showed a unimodal trend，peaking during the day and decreasing at night. The initiation time of transpiration of undegraded and lightly degraded P. simonii was earlier than that of moderately and severely degraded P. simonii，and the peak transpiration rate of undegraded P. simonii was significantly higher than that of the other three degrees of degraded P. simonii. 2）The daily water consumption of P. simonii with different degradation degrees during the growing season showed a seasonal trend of first increasing and then decreasing， and the daily water consumption generally followed the order of undegraded > lightly degraded > moderately degraded > severely degraded. The peak daily water consumption of undegraded P. simonii（197.19±38.99）L was 2.4，3.3，and 3.9 times that of lightly degraded（82.43±5.30）L， moderately degraded （62.06±6.79） L， and severely degraded P. simonii （51.02±7.00） L， respectively. Degradation shortened the growing season of P. simonii，with the growing season of moderately and severely degraded P. simonii lasting from May to September. 3）The transpiration rate and daily water consumption of P. simonii with different degradation degrees during the growing season was extremely significantly correlated with photosynthetically active radiation，wind speed，air temperature，vapor pressure deficit and relative humidity. The daily water consumption of undegraded and lightly degraded P. simonii during the growing season showed a significant negative correlation with precipitation. There were differences in the responses of transpiration rate and daily water consumption to meteorological factors among P. simonii with different degradation degrees，and multiple meteorological factors jointly controlled the transpiration rate and daily water consumption of P. simonii. ［Conclusion］The results can provide a theoretical basis for estimating the ecological water demand and selecting appropriate stand density of P. simonii plantations in the Bashang area under balanced water conditions.