Abstract: In order to explore the size effect of cycling dynamic characteristics of rock, the cyclic impact tests for the granite specimens with height-diameter ratios of 1.00, 0.76 and 0.50 are carried out using the split Hopkinson pressure bar, and the testing results are compared and analyzed. The analysis results show that under the same striking velocity, the post-peak failure stage of the last stress-strain curve of the specimen is more significant under a smaller height-diameter ratio. With the increase of the height-diameter ratio, the peak strain of the specimen decreases as the whole, while the elastic moduli of the specimens increase and the decreasing degree of peak stress obviously becomes weak. Under the cyclic impact of the same incident wave, the upward trend of cumulative specific energy gradually decreases with the increase of the height-diameter ratio. Under the cyclic impact of low striking velocity (i.e., 8.5 m/s), the longitudinal cracks appear, which presents the failure mode of axial splitting, while at a high striking velocity (i.e., 9.9 m/s), the failure mode of the specimen changes from the axial splitting to a small number of flakes at the periphery. In addition, the fracture degree of the specimen decreases with the increasing height-diameter ratio, and the volume of fragments increases while the number of fragments decreases.