[Objectives] We observed the testicular microstructure of Feirana taihangnicus throughout the annual reproductive cycle to investigate its reproductive pattern. [Methods] We used histological techniques (including hematoxylin-eosin method and micro-measurement technique) to observe the testicular microstructures of F. taihangnicus in different months. The diameter of seminiferous tubules and the area of testicular interstitial regions were measured and recorded. The relevant data were analyzed by ANOVA and multiple comparisons. All statistics were performed in SPSS 22.0. [Results] The diameter of seminiferous tubules, the structure of seminiferous tubules, and the area of testicular interstitial regions in F. taihangnicus exhibited distinct annual cyclical changes. The diameter of seminiferous tubules was at its maximum when F. taihangnicus emerged from hibernation in March. During the breeding season in April, the diameter of seminiferous tubules showed no significant change compared with that at the time of emergence from hibernation (Tables 2, 3). In May, when the breeding season ended, the diameter of seminiferous tubules reached the minimum value in the annual cycle. From July to August, the peak period of spermatogenesis, the diameter of seminiferous tubules increased significantly (Tables 2, 3). In October, as F. taihangnicus was about to enter hibernation, the diameter of seminiferous tubules was already close to the maximum value (Tables 2, 3). The spermatogenetic cycle of F. taihangnicus showed a discontinuous type. It took one year from spermatogonial proliferation to spermiation. The spermatogenetic cycle of F. taihangnicus comprised five stages with significant features. Spermatogonial proliferation lasted from June to July, when spermatogonia proliferated extensively and formed numerous spermatogenic cysts within the seminiferous tubules, and a new round of spermatogenesis started. The meiotic division period of spermatocytes was from July to August. The primary spermatogonias within spermatogenic cysts underwent two successive meiotic divisions to form a large number of spermatids. Sperm formation was from August to September, when the spermatids within spermatogenic cysts underwent a process of maturation known as spermiogenesis to form bundles of spermatozoa. Sperm storage was from October to March of the following year. The spermatozoa were distributed in bundles within seminiferous tubules and matured after hibernation. As the maturity of spermatozoa increased, the motility gradually strengthened, and thus the arrangement in seminiferous tubules became more disordered. Sperm expulsion was from the end of April to May of the following year, when most of the spermatozoa in the seminiferous tubules were expelled from the body. Meanwhile, the diameter of seminiferous tubules was significantly reduced, and a small amount of spermatozoa and shed sertoli cells remained in the lumen. While only a single layer of spermatogonia and a few sertoli cells remained on the tubule wall (Fig. 3). During the breeding period, the interstitial regions of the testis were clearly visible. There were many interstitial cells around the seminiferous tubules, which were large in volume. Shortly after the end of the breeding period, the area of testicular interstitial regions reached its peak, and then gradually decreased, reaching its minimum before hibernation. During hibernation, there was no significant change in the interstitial area. After emerging from hibernation, the interstitial area showed almost unchanged compared with that before hibernation (Tables 5, 6). Interstitial cells showed marked morphological changes before and after breeding, playing a key role in regulating sex hormone synthesis and secretion. This might explain the appearance and disappearance of secondary sexual characteristics in male F. taihangnicus. [Conclusion] Significant seasonal variations were observed in the testicular microstructure of F. taihangnicus. The spermatogenesis in F. taihangnicus started in June and ended in May next year. The spermatogenetic cycle of F. taihangnicus is similar to that of other reported anuran amphibians, both consists of five stages: spermatogonial proliferation, meiosis of spermatocytes, sperm formation, sperm storage, and sperm release. However, there are some differences in the start and end time of each stage between different species (Table 7). The results enrich the basic information of amphibian reproductive biology and lay a foundation for the breeding and conservation of F. taihangnicus.