Abstract: More than 1/3 of natural grassland in China is degradation. The policy of returning grazing land to grassland is an important way to combat with grassland degradation. However,returning grazing land to grassland also leads to illegal grazing. The game theory was applied here to analyze the strategies of players,i.e. government and herdsman household. We explored the optimal strategies and simulated them. The results showed that:there were several ways to restrain the illegal grazing,including increasing the probability of illegal grazing detected,reducing inspection costs,and increasing the amount of fines. It is suggested that living patterns of herdsman households should be changed from scattered to centralized;the person,who carries out the inspection of illegal grazing behavior,could be recruited widely in society;the supervised regions should be divided clearly and normally inspected by resident staffs;and the amount of the fine should be determined according to special conditions. This study is helpful for drawing up the countermeasures of illegal grazing behavior and for promoting the coordinated development of population,resources and environment.

Key words: Game theory, Grazing, Returning grazing land to grassland

摘要： 中国超过1/3的天然草地处于退化、沙化状态。退牧还草政策是应对草地退化的重要措施。退牧还草政策实施过程中常有违规放牧现象。本文采用博弈论方法，分析牧户和政府双方的策略集合，得出最优策略，并进行模拟计算。结果表明：提高违规放牧被检查到的概率，降低检查成本和增加罚款金额等措施，可促使牧户减少违规放牧行为。据此，我们提出减少或者杜绝违规放牧行为的措施主要包括：规划安置点将牧户由分散居住转为集中居住；违规放牧行为的检查工作由社会招聘监察人员和牧户监督员承担；划定管护责任区域，由常驻人员进行管护区域内的违规放牧检查工作；根据各地具体情况，设置合理罚款金额。本研究可为制定遏制违规放牧的对策提供依据，促进草原地区人口、资源和环境的协调发展。

关键词: 博弈论, 放牧, 退牧还草