法定地上權成立要件之解釋與適用，影響抵押權實行時拍定人、建物與土地所有人、抵押權人、抵押人等之權益甚鉅，實有仔細探究之必要，尤其是針對於「設定抵押權時土地建物同屬一人」之「同屬一人」要件，是否應予以擴張解釋一事上，同一事件歷經最高法院97年、98年及99年之三次判決，意見上並不一致，考量因素上亦有不同，具有深究之價值。考察我國民法第876條之立法理由，本文認為，法定地上權之成立理由上，應注意其具有彌補法制上建物所有人不能設定自己土地利用權之功能，立論基礎上，不能忽略其對於私益之保護觀點，而各成立要件之重要前提則是，必須基於顯見客觀之事實關係。參考日本對於法定地上權各個成立要件上，雖有採行柔軟態度之趨勢，但針對抵押權設定時土地及建物必須同屬一人之要件，則堅採嚴格解釋，其理由根據在於，利用關係之當事人於法律上既然有約定之可能，法律自然無需介入，而此正能呼應的是，本法具有彌補不能設定自己利用權之功能目的，再者，本文認為擴張同屬一人概念至親密感情間之親屬，不符法定地上權成立要件應具有之客觀公示性質，且自抵押權設定至抵押物拍賣期間，親屬關係之變化將致事實認定產生困難。至於如立法論上決定，為了避免拆毀建物而擴大法定地上權之適用範圍，此由活化使用土地之人其生活關係與企業組織之觀點言之，的確具有社會性之作用，而我國法律政策上是否採此，則已脫離本法之文義解釋範圍，當可為另一討論議題。

The explanation and interpretation of the legal requirements for statutory superficies in Article 876 of Civil Code will certainly affect the rights of bidder, the owner of the land and the building, the mortgagee, and the mortgagor. Disputes exists among the decisions of our Supreme Court especially on the explanations for the ＂If the land and a building on such land are both owned by the same person at the time a mortgage is created…＂ of Paragraph 1, Article 876 of Civil Code. What is the proper limit of explanation ＂owned by the same person＂ should be thoroughly investigated. After examining the legislative cause and purpose of our Article 876 of Civil Code, this essay holds that since the statutory superficies of such article is aimed to make up for the loophole in our legislation that the building owner cannot create any rights on his own real property, therefore, there leaves no room to apply this article to such conditions when agreement regarding the right on the land already been made or should have chance to be made (with special reference to the members of the same family) between the owners of building and the land. This essay also holds that the ＂owned by the same person＂ requirement of statutory superficies being deemed to have been created should be based on objective matter of fact in order to meet the ＂principle of public summons＂. Accordingly, this essay excludes from applying Article 876 of Civil Code the intriguing situations which the building and the land owned by the same ＂family＂ or by the close ＂family group＂ in spite of the extremely intimate and tight relationships existing among the family members, since the intimate relationship between family members is difficult to qualify and might alter and hence lack the crucial character of public summons for the third person to realized. Before the legislative policy clearly switches otherwise, this essay holds that the limit of explanations for the ＂owned by the same person＂ in Article 876 of Civil Code should be carefully demarcated.