幹細胞具有修復人體組織與維持其功能之生物特性，臍帶血幹細胞由於取得容易、相容性要求較低之特性，使其基礎研究與臨床運用成為臨床醫學之顯學。不惟如此，民間亦興起收集並存放臍帶血幹細胞之一股風潮，然而對臍帶血幹細胞與其衍生物之法律性質，文獻上仍少有深入探討者。 探討臍帶血幹細胞及其衍生物之法律性質，非僅具學術意義而已，實牽動著此高科技產物物權歸屬之判斷。本文首先肯認臍帶血幹細胞與其衍生物為所有權適格之客體，次以我國民法物權之理論為基礎，輔以解剖學、生理學以及遺傳基因學等生物醫學上之事實，駁斥臍帶血幹細胞所有權屬於新生兒之通說，而認為臍帶血幹細胞所有權應歸屬於母體，並進一步認為臍帶血幹細胞之衍生過程，應適用民法加工之規定，而非屬於天然孳息。

The umbilical cord blood stem cell gains prevailing advantages over bone marrow and fetal stem cell in both technical and ethical aspect6s, which makes the business community recognize that umbilical cord blood cell transplant technology could yield significant financial profit. In Taiwan it has stimulated a ready market for blood storage, and several companies offering private storage and some charity community offering public umbilical cord blood banks now exist, which make the prevalence of umbilical cord blood stem cell storage rate estimated up to 4 per 100 births in this country. The umbilical cord stem cells, used to be regarded as delivery wastes, appear in itself legally a brand new issue both on personal rights and property rights which have never been well elaborated in the past. Disputes are certainly to arise since the umbilical cord blood stem cell so valuable a kind of substance, which urges us to pay more attention. This article elaborates mainly the ownership of the umbilical cord blood stem cells and its derivatives. The srong classic concepts are fully presented, and meanwhile this article address that mothers have the entitlement to ownership of the umbilical cord blood stem cell by all the legal, anatomical, biological, and genetic aspects. Also this article holds that the derivative inducing process of umbilical cord blood stem cell is not kind of natural breeding as coded in article 69 and 766 of Civil Code, but that of the processing work as coded in Article 784 of civil Code.