自1996年3月至1997年8月之間，每月至採集地捕捉成熟赤尾青竹絲，共捕捉134隻雌蛇及154隻雄蛇；平均每月捕捉雌蛇7隻、雄蛇9隻。本研究以生殖器官形態、組織切片及血清性賀爾蒙三方面來探討其生殖週期型式。在雌蛇的生殖週期方面，我依照卵巢內濾泡大小及黃體之有無，將成熟雌蛇個體分為七個生殖時期。第一期個體只具初級濾泡，最大濾泡長度小於5 mm，屬於未生殖群；第二至六期個體具次級濾泡，最大濾泡長度分別為5- 10 mm, 10- 15 mm, 15- 20 mm, 20- 25 mm, 及25 mm以上，第七期個體具初級濾泡及黃體；第二至七期個體為生殖群。濾泡由第二期個體開始逐漸增大，第五期個體處於排卵前期狀態，其血清動情素是各時期中較高的。第六期個體為已排卵者，其血清助孕素為各時期中最高者。隨著生殖時期期數增加，脂肪量會逐漸下降。由於實驗期間所捕獲之生殖群與未生殖群個體數相當，我認為赤尾青竹絲雌蛇生殖頻率為二年一次。脂肪量應為赤尾青竹絲雌蛇生殖頻率的主要限制因子，未生殖個體可能在累積一定脂肪量後方成為生殖群。生殖群個體在形態、組織、激素三方面均具有明顯的年週期變化。其濾泡於秋季開始持續增長，於隔年春末排卵，再於夏季生產；屬於婚後型 (第二型) 卵黃形成作用。生殖群個體隨著濾泡成長，其輸卵管上皮細胞高度及輸卵管腺外徑亦變大，未生殖群個體則否。在雄蛇的生殖週期方面，睪丸細精管生殖上皮細胞形態隨著生殖進展可分為回復期早期、回復期晚期、生精期、萎縮期早期、萎縮期晚期五期。由各時期在各月份之比率可看出顯著的年週期變化；生殖上皮細胞於3月開始回復，夏、秋二季為主要生精作用發生時期，冬季則為萎縮期。睪固酮於七月有一高峰值。睪丸形質及生殖上皮相關因子，包括細精管外徑、細精管生殖上皮高度、細精管生殖上皮細胞層數，亦於整個冬季及初春達最低，之後開始回復，而於夏、秋二季達高峰；屬於婚後型 (第一型) 成精作用。雄蛇之成精作用及睪丸相關因子之變化與脂肪、溫度及雨量間有著顯著相關性；其成精作用發生於環境溫度逐漸升高時。腎小管性節外徑亦具明顯月變化，但其達高峰的時期較睪丸方面遲，可能與交配活動有關。雄蛇脂肪量並未隨著生殖作用進展而下降，其高峰值亦是在夏、秋二季。我認為這可能是夏、秋二季食物量多，雄蛇於此時攝食率高，所攝取的能量較生殖作用消耗者來得高，故其淨值仍較高。而秋、冬交配季節攝食率低，消耗的能量相對較多，故脂肪量下降。由於赤尾青竹絲雌雄蛇均可貯精，可在輸卵管陰道區及漏斗區發現貯精構造，故赤尾青竹絲似乎有能力於其他季節 (例如春、夏季) 交配之。但此推論仍須進一步證據支持。

I studied the reproductive cycle of Chinese green tree vipers, Trimeresurus s. stejnegeri in northern Taiwan by examining seasonal changes in the morphology and histology of their reproductive organ and the hormonal activity. From March 1996 to August 1997, I collected a total of 288 snakes with an average of 7 female and 9 male snakes per month. Based on the size of follicles and the presence of corpora lutea, I classified mature female snakes into 7 stages. The snakes in the first stage had only primary follicles of which the maximal length is less than 5 mm. The snakes that belonged to stage 2 to stage 6 had secondary follicles with the length ranged between 5- 10 mm, 10- 15 mm, 15- 20 mm, 20- 25 mm and above 25 mm respectively. The last stage snakes had both primary follicles and corpora lutea. I found estrogen level was highest in the snakes of stage 5 while that in stage 6 had the peak concentration of progesterone in serum. The numbers of reproductive females which belong to stage 2 to 7 versus that of nonreproductive females, classified in first stage, was close to unity. This suggested that female T. s. stejnegeri reproduced biennially rather than annually. The mass of fat body correlated negatively with the process from first stage to last stage. Fat reserves may become the limiting factor of reproductive frequency. Female Chinese green tree vipers had seasonal cyclic changes in morphology and histology of reproducitve organs as well as hormonal activities. Their timing of vitellogenesis belongs to postnuptial type (type II) vitellogenesis, which is common in the viperids.According to the morphological difference of seminiferous epithelium, I classified male Chinese green tree vipers into five stages, which were early recrudescence, late recrudescence, spermiogenesis, early regression and late regression. Early recrudenscence stage started from March and could last till May. Spermiogenesis stage occurred mainly in summer and autum. While in winter, I found most male snakes belonged to regression stages. Other parameters, such as diameter of seminiferous tubule, renal sexual segment and fat body mass also revealed seasonal cylcic changes. However the peak of each cycling may not be the same. For example, the peak of renal sexual segment diameter, which correlate well with copulation was later than that of seminiferous tubule diameter. The same as many other viperids, male Chinese green tree vipers had postnuptial spermaotgenesis cycle.