中文摘要：

根据交易费用产生的来源将产权公共域分为两种类型，讨论这两种产权公共域对被征地农民的土地产权侵害。在农地征收过程中，由于对农地资源价值属性认识上的不足、农地资源价值量化与测算上的困难以及高昂的交易费用，使得一部分农地产权留置于公共域中，最终影响农地产权人得到的价格或补偿。江苏省江都市的实证分析表明，农地产权公共域造成农民及其集体的土地权益受到侵害，使农地征收价格减少74％。如果征地按照市场价格对农民及其集体进行补偿，那么其土地财产权益可以增加到9倍以上。

英文摘要：

Property rights in the public domain are divided into two kinds based on the source of transaction cost, and property infraction of farmers whose farmland is expropriated are discussed because of the property rights in the public domain. In the course of farmland expropriation, some parts of farmland properties are placed in the public domain because of limitation on the knowledge of farmland＇s function attributes, difficulties of measuring these at- tributes accurately and high transaction costs, which will affect price or compensation that farmland property rights partners can obtain. By a case study of Jiangdu in Jiangsu Province, the interests and benefits of farmers and their collective are infracted because of the farmland property rights in the public domain, which makes about 74 percent reduction of farmland expropriation price. The interests and benefits of farmers and their collective can be added to 9 times if it is compensated by market price in the course of farmland expropriation.