Ninety three adult male Bowring's geckoes ( Hemidactylus bowringii ) were collected in Fuzhou, Fujian, China during the active seasons from June, 1996 to March, 1998. The results from the study indicated that testis size, including weight and volume, was smallest in September and reached a peak in next June. In late September, both seminiferous tubule diameter and epithelial height were smallest, and spermatogonia were the most prevalent type of cell. Tubule diameter and epithelial height increased from October. At the end of October and the beginning of November, some spermatozoa appeared in seminiferous tubule cavity. The epithelial height was the largest in December, indicating that spermatogenesis was considerably active. There were some spermatozoa in different ducts at this time. Because the releasing of mature spermatozoa and spermatogenesis was bogged down during hibernation, the tubule diameter and epithelial height both decreased greater in March than in December, and both of them increased again after March. The tubule diameter reached a maximum size in June, corresponding to peak spermatogenesis. The most prevalent cells at this time were spermatids and spermatozoa. The tubule diameter decreased from July, but the epithelium from May to September.