Abstract: In order to investigate whether there were differences in the results of leaf force-to-punch under different calibration methods and different puncture needle diameters,and the relationship between the results and leaf functional traits,30 dicotyledonous species were selected to determine the punching force and the tearing force of the leaves and the functional traits of leaves under three puncture needle diameters of 2.0,1.0and 0.5 mm,respectively.The results showed that:（1）the leaf force-to-punch differed significantly（P＜0.05） among the three different puncture needle diameters,for the same species when the method calibrated by perimeter,the difference between 0.5 mm and 1.0 mm was 76%,between 0.5 mm and 2.0 mm was 76%,and between 1.0 mm and 2.0 mm was 33%（P＜0.05）;however,when calibrated by cross-sectional area,the difference was 66%,56% and 30%（P＜0.05） respectively.（2）There was no significant difference in leaf force to punch between the three puncture needle diameters under different calibration methods in the same life form,but there was significant differences（P＜0.05） between herbs and different life form such as shrubs and trees,respectively,while the leaf force-to-punch of 0.5 mm diameter needles was greater than that of 1 and 2 mm needles.（3）Leaf force to punch was significantly positively correlated with leaf cuticle thickness,leaf thickness,and leaf tearing force（P＜0.05）,and negatively correlated with specific leaf area（P＜0.05）,and the correlation between punching force calibrated by needle circumference and leaf functional traits was stronger than that calibrated by cross-sectional area,whereas there was no significant difference in the correlation between leaf force to punch and leaf traits under the action of different diameters of puncture needles.Therefore,differences in both needle diameter and calibration methods produced differences in the results of leaf force to punch measurements.Differences in needle diameters did not affect the correlation between mechanical punching force and leaf functional traits,whereas differences in calibration methods affected the strength of the correlation between mechanical punching force and leaf functional traits.In conclusion,in the leaf force to punch research,selecting the appropriate calibration method and puncture needle diameter was conducive to improving the standardization and accuracy of the data,it was recommended that the two calibration methods based on the needle perimeter should be selected first,and among the three types of puncture needle diameter,0.5 mm was selected to measure with small leaf area and dense and thin veins,and 2.0 mm was selected to measure with large leaf area and,dense and stiff veins.