借貸因借用人是否需交付擔保品，唐人分為信用借貸與質押借貸兩類。質押借貸中，動產質的運用比不動產質、人質更方便而普遍。本文就以動產質為例，說明唐代的質借制度及其作用。 動產質是指出質人將財物等動產,移轉交付給質權人，而於一定期限清償債務後，贖回質物的制度。唐代從事動產質借業務者，除官吏、商賈或一般百姓外，寺院道觀或僧道個人也不乏其例。其分布地點遍及城市與鄉村，中央與邊區，其規樸大小不等，有專業性的質庫，兼營質業的一般店鋪,或個人偶然為之。持質物來借貸者，多為生活貧困的百姓,但有些 則是借此融資的大商人。 動產質借的期限與利率，因所借物種而異，質借穀物類者多是春借秋還，計年利率，質借貨幣類者則隨時可借、還，多計月利率。動產質借數量一般不大，以小額借貸居多。質期屆滿，出質人應清償債務，贖回質物。如出質人不如期回贖，則質權人可賣質物折債，或擁有該物之所有權。但質權人在處理該質物時，應在官府的監督下進行。

　　　　　In the Chinese history, the lending practice , which was divided into two categories , the credit lending and the mortgage lending , depends on whether the borrower was required to submit the collateral. Among the mortgage lending, the utilization of liquid assets as collateral was far more prevalent and convenient than real estates or hostage. This article adopts the property lien as an example to illustrate the lending system and its functions in the T'ang dynasty. Property lien lending pertains to the system where the pledger transfers liquid assets to the lien holder, and repays the debt within a certain period of time and redeems the collateral. In addition to officials, merchants, or common civilians, there were ample examples of the buddhist, toist temples, or even the individual monks themselves that were engaged in the property lien lending operations in the T'ang dynasty. The distribution scattered throughout cities and villages, at the capital or remote frontiers. Its scales varied as there were professional chih-k'u, or general stores that also operated on property lien, or occasional personal acts. Those who submitted collateral for loans were mostly poor civilians, but there were also successful merchants who borrowed for financing purpose. The duration and interest rate for property lien lending varied with the type of collaterals. Those who borrowed crops tended to borrow in the spring and redeem in the fall, with the interests calculated at an annual rate, while those who borrowed currency may borrow or return at any time, with the interests calculated on a monthly basis. Most of the property lien lending tended to be modest, with small amount of borrowing as the majority. Upon the expiration of the property lien lending, the pledger should clear the debt and redeem the collateral. If the pledger failed to redeem within the specified period of time, the lien holder may liquidate the collateral to clear the debt, or assume the ownership to that collateral. But when the lien holder was liquidating that collateral, it ought to be conducted under the supervision of the official authority.