民法第864 條「抵押權之效力，及於抵押物扣押後抵押人就抵押物得收取之法 定孳息」，具有調和抵押權人、不動產所有人與用益權人權益之功能，但因租金 債權之支分權特性，在租金債權之債權讓與及抵銷之適用上，可能衍生諸多疑義，最高法院102 年度台上字第44 號民事判決，即為抵銷適用爭執之事件。抵押 權之核心精神在於掌握抵押物之「交換價值」，本不應及於使用收益權能之租 金，然而為鞏固抵押權之信用、防止拍賣手續之延遲，故僅以扣押後之期間為 限，租金為抵押權效力所及。將來債權讓與效力發生之時間點，乃係於時間經過 後、各期支分權實際發生時，始生債權移轉效力，而抵押權之效力則是於抵押權 設定完成時即已發生，依此，即使查封前已有債權讓與契約，然而因為其讓與生 效時間點係在「查封後」，且將來債權讓與時之權利移轉過程，仍須是先發生於 讓與人後方歸屬於受讓人，依物權之排他性原則，抵押權之效力乃優先於債權讓 與。當抵銷權與我國民法第864 條效力及於扣押後租金之抵押權二者競合時，不論 依租金債權發生時間點與租金債權發生根據二觀點切入，均應以查封時，作為被 動債權之租金債權清償期屆至已否做為區別，查封後清償期方屆至之租金債權， 由抵押權優先於抵銷效力，除此以外，承租人當然有抵銷權，而於約定抵銷亦相 同適用此一原則。

The Article 864 of Civil Code, which stipulates “The effect of a mortgage extends to statutory Interest that the mortgagor is entitled to collect on the mortgaged property after the attachment of such property”, is aimed to make a reconciliation of the rights among mortgagee, mortgagor and usufructuary. However, the dispute still arises such as whether the mortgagor is entitled to transfer the claim of rent after the attachment of the mortgaged property, or the lessee is entitled to offset the obligation of rent as was demonstrated in Supreme Court Tai-Shan-Zi No. 44 (2003) Decision. This article holds that the general mortgage is not only a superior right of a creditor to receive satisfaction of a claim from the proceeds, but also is entitled to the rent after the attachment of the mortgaged property. Besides, based on the nature of claim of rent, which presents periodically and falls due at sated intervals, the deposition of the claims of rent, including transfer and offset, will not effect until maturity. Accordingly, even though the mortgagor transfers the claim of rent before the attachment of the mortgaged property, yet the effect of a mortgage extends to the claims of rent which could be exercised after attachment. Moreover, when the mortgaged property has been attached by an order of the court, and if the lessee has acquired a claim from the creditor before the attachment, and on if the claims of rent already mature before the attachment, he is entitled to offset the obligation, otherwise, the general mortgagee is entitled to the rent after the attachment of the mortgaged p roperty which the mortgagor is entitled to collect.