本稿詳細整理和塑述漢譯佛書七日為週期、三十八個七日滿足的七日住胎論思想，又將它置於印度古典醫學的背景上，看出它跟醫方明以月為週期、九個月滿足的住胎論大不相同，而僅行於佛教以內；再考究漢譯阿含部經典，發現阿含部的住胎論跟醫方明大體一致，則知七日住胎論可能是大乘佛教發展出來的，為原始佛教所無。 　　一般以為上述七日住胎論對支那醫學沒有影響。本稿舉出西元五世紀以降多種道教、醫學乃至民眾文藝、雜家等文籍，證明其中有七日胎相論，是受自不同的漢譯佛書，且總的趨勢是愈加被認可。進入支那思想領域之後，思想形態上七日住胎論顯著的表現是：作為胚胎自我展現動力的業風 (las-kyi rlung) 被忽略，三十八個七日的胚胎展現過程變成了逐個七日胎相的機械羅列。這樣它就很像《徐之才逐月養胎方》等支那既有妊娠論的樣子，而且胚胎開始時甚至沒有主體（投胎者），妊娠變成沒有目的的成長、沒有主體的發育。這是因為受到支那既有妊娠思想的潛在制約。 　　本稿屬於思想史和文獻學的研討，著意使用豐富資料和比較的方法。漢、藏文獻的比較，支那、印度的比較，醫方明、佛教醫學的比較，或者有助主題的闡明。

This paper elaborates on the thought of the seven day embryo formation theory found in the Chinese version of Buddhist books. This theory holds that seven days constitute a cycle and that 38 such cycles is the period needed to form a fetus. The thought is set in the background of Indian classical medicine and is confined to Buddhism. It differs greatly from “Gso-ba Rig-pa” (醫方明) which believes that a month constitutes a cycle and that nine months is the period needed to form a fetus. After referring to the classics of Āgama, I discovered that the theory of embryo formation found in “Gso-ba Rig-pa” is generally similar to that of Āgama, from which we may deduce that the seven day embryo formation theory is derived from Mahāyāna Buddhism and is not found in original Buddhism. It was generally believed that the theory mentioned above exerted no influence on Chinese medicine. In this paper, I list a variety of books on Taoism, medicine, popular literature, and miscellaneous writers to prove that the theory on seven day embryo formation, originating from the Chinese version of Buddhist books, is mentioned and has come to be recognized. After its entry into the Chinese domain of thought, some noteworthy aspects of the theory on seven day embryo formation displayed in terms of thought is as follows: the “las-kyi rlung” (業風) through which the embryo demonstrates its dynamism is neglected, and the process of 38 seven days of embryo formation has developed into a mechanical listing of separate seven day embryo formations. This theory thus resembles established Chinese theories on pregnancy such as Xu Zhicai’s Prescriptions on Pregnancy. It is believed that at the beginning of embryonic development, the embryo does not have subjectivity, (reincarnation) and therefore pregnancy becomes a process of aimless growth and development without subjectivity. This theory has been influenced by established Chinese theories on pregnancy. 　　This paper falls into the category of research and discussion on ideological History and Philology. It employs a large amount of data and numerous methods of comparison, including comparisons between Chinese and Tibetan literature, China and India, and “Gso-ba Rig-pa” and Buddhist medicine, all of which may contribute to research on this subject.