土地徵收係國家為興辦國防、交通、公用等公共事業時，基於公益之需要，在事業必須使用之範圍內，依法定程序剝奪人民財產權之手段。我國土地徵收於土地法及其他法規中之規定並不一致，為統一徵收程序，民國89年制訂土地徵收條例，該法第1條規定：「為實施土地徵收，促進土地利用，增進公共利益，保障私人財產，特制定本條例。土地徵收，依本條例之規定，本條例未規定者，適用其他法律之規定。其他法律有關徵收程序、徵收補償標準與本條例牴觸者，優先適用本條例。」第11條規定：「需用土地人申請徵收土地或土地改良物前，除國防、交通、水利、公共衛生或環境保護事業，因公共安全急需使用土地未及與土地所有權人協議者外，應先與所有權人協議價購或以其他方式取得；所有權人拒絕參與協議或經開會未能達成協議者，始得依本條例申請徵收。」土地徵收條例嗣為土地徵收之準據。惟協議價購之性質，是否如實務一向見解所認為單純之私法契約，或因其隱藏於背後之目的，而具有公法行政契約之性質？此外，依該條例第9條規定，徵收完成後，需用土地人怠於執行興辦計畫，或雖依原核准計畫辦理後，於一定年限內不依原計畫繼續使用徵收之土地時，原土地所有權人得依法申請繳回原徵收價額後，買回其被徵收之土地。則協議價購之原所有權人於該土地有前開情形時，是否亦享有收回權？該等問題為本文研析之重點，並試提出相關理論依據及研究心得，以為土地徵收條例修正時之參考。

To meet the requirement of public welfare the state may compulsorily purchase private land for installations of national defense and communication enterprises and public utility enterprises, but the area of land to be compulsorily purchased shall be limited. However, Taiwan's land expropriation in the Land Law and other laws and regulations are not consistent. In order to impose uniform compulsory purchase procedures, the Government developed The Compulsory Purchase Act in 2000. Rule 1 of the Act states: "The purposes of this Act are to implement the land expropriation, to promote land utilities, to increase public profits, and to protect private properties. According to this Act, the land expropriation must obey the regulations of this Act. If it is not stipulated by this Act, the regulations stipulated by other laws are suitable. The compulsory purchase procedures stipulated by other laws and the compulsory purchase compensation standard violated this Act are first suitable to this Act." Rule 11 of the Act stipulates: "People who needs the lands should first obtain the agreement with land owners or acquire the lands by other ways. This action must be completed before applying for the land compulsory purchase or the improvement to land. The exemption is: due to the requirement of the public security, such as national defense, public traffic, water conservancy, public health, and environmental conservation, there is no time to obtain the agreements with the land owners to acquire their lands. If the land owners refuse to attend the meeting or cannot reach the agreements, the administrations can apply for the land compulsory purchase according to this rule." The Compulsory Purchase Act is the standards for the land expropriation. Whether the characters of the agreement concerning the amount of compensation likes the practical opinions that simply belong to the contracts of private laws, or due to the reasons in the behind have the characters of the administrative contract of public laws? In addition, Rule 9 of this act also stipulates that after the accomplishment of the land expropriation, if the people who need land can not implement the plan or, execute the plan in accordance with the approved one, but no longer follow the original plan to continue to use within a certain time period, the original landowners can pay back the original amount of the compensation for its redemption. Whether the original land owners have the rights to pay back the original amount of the compensation for its redemption under the above condition? The purpose of this paper is to study the aforementioned questions. The related theories and research attainments will be demonstrated. The results can be the references for the amendments of the Compulsory Purchase Act in the future.