中文摘要：

先占是一种重要的私人财产权获取方式和原则。其合理性在于先占人的资格比较容易识别，且一般蕴含着尊重劳动及征得他人同意、先占人与其他人之间存在着明示或默示契约之意。通过加利福尼亚淘金热中先占原则的历史变迁，阐明了不同变量对先占原则的影响，并进一步说明先占原则的有效性取决于资源的状况、先占者与他方的力量对比、是否需要合作、信息费用、权利的维护成本等诸多因素。权利冲突现象的广泛存在，更进一步解释了现代社会先占原则式微的原因。但市场定价制度的非精确性，却使先占原则以“排队伦理”的形式获得了新生。

英文摘要：

Preemption is an important method and principle of getting private property rights, the systematic basis of which is that it＇ s easy to tell the qualification of the first nullius, and there exist explicit or implicit contracts between the first nullius and the others. According to its historic changes in California Gold Rush, it was explained that the variables, such as resources, balance of power, cooperation, information fee and costs of rights, have influences on principle of preemption and validity of the princi- ple. And the reason why principle of preemption is less important in modem society can be found from the universe existence of rights conflict. However, the principle of preemption obtains a new reborn in form of waiting ethics, based on the imprecision of price system in modem society.