the purpose of this paper was to analyze the changes of poplar sap flow, to explore the meteorological factors affecting the changes of poplar sap flow and their response laws, so as to provide a theoretical basis for the follow-up study on the improvement of poplar living tree and the rising mechanism of its liquid medicine. the sap flow rate of poplar was measured by flow 32a-1k wrapped sap flow meter, and meteorological factors were measured simultaneously by solar meter and temperature and humidity meter. the results showed that there was a significant positive correlation between poplar stem velocity and solar radiation intensity and air temperature, but a negative correlation with air relative humidity. therefore, the influence degree of different meteorological factors on poplar sap flow rate is different.