探討臍帶血幹細胞之所有權歸屬，非僅具學術意義而已，實牽動著此高科技產物相關契約效力之判斷。關於臍帶血幹細胞之所有權歸屬，通說咸認為應屬於新生兒所有，其根據多基於民法第7條之胎兒擬制權利地位及生物遺傳學上兩種理由。惟民法第7條雖可擬制胎兒權利主體之地位，但並未能擬制與人體分離前之臍帶血物權業已發生，將發生有權利主體卻無權利客體之問題。再者，以基因組態決定臍帶血與幹細胞所有權歸屬，將無視於人體組織由何處分離、何時分離、是否已分離等過程，此無異於在一個具有權利能力之人體上，論斷其身體一部分組織之物權歸屬於另一個權利主體，故本文不採。 本文認為，臍帶組織在被截斷與胎兒之連結後，胎盤、臍帶、臍帶血之整體，仍與母體子宮相附著，看似已成為「物」之胎盤、臍帶、臍帶血，事實上仍為母體人體之一部分，故此際該動產物權尚未發生，新生兒無由主張所有權，嗣臍帶與胎盤同時自母體分離之後，始發生臍帶與胎盤之動產物權，並適用物權法理由所由分離之人的母親取得其所有權。 本文進一步詳析，臍帶血幹細胞所有權人之不同認定與其搞贈及自存契約效力之關係。倘本文之見解可採，母親可基於臍帶血所有權人立場，為各式的債權行為及物權行為，故宜以母親為臍帶血所有權人以及契約當事人之地位訂立契約。另由於母親存放臍帶血時，多以子女未來可能之使用為儲存動機，為讓子女能有效利用該臍帶血幹細胞，本文建議，母親可在與臍帶血存放機構訂立存放契約時，同時訂立贈與契約。藉此贈與契約之訂立，能讓母親為子女預存臍帶血之意志得以完整實現，用臍帶血幹細胞之利用也會更為有效。這是探討臍帶血幹細胞正確所有權歸屬後明顯可見的具體實益之一。

Both the medical and business communities recognize that umbilical cord blood cell transplant technology could yield remarkable medical and financial profit. Several companies offering private storage and some charity community offering public umbilical cord blood banks now exist in Taiwan, 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 on property right which has 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. The wrong 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 examined the validity of the clauses of umbilical cord blood deposit contracts according to different concepts regarding the ownership of cord blood stem cell.