本文建構一個多廠商經營之生態旅遊模型，分析生態旅遊與自然資源之間的動態平衡；並進一步分析應如何制訂相關的管制政策，以避免或解決生態旅遊對於自然資源過度開發的問題。我們分別從廠商數為外生（透過政策直接管制），和內生（透過政策間接決定均衡廠商家數）兩種設定，探討生態旅遊的均衡，並透過比較靜態來分析對應的管制政策。我們發現：(1) 在多廠商經營之下，自然生態資源可能出現高或低存量的均衡；(2) 造成較低生態存量（或稱過度開發）的原因有：經營廠商家數過多、潛在遊客過多而且無數量限制；(3) 因此，避免多家業者經營下所出現低存量均衡，則可以分別透過對廠商與對旅遊者的適當政策來達成，如提高經營者之許可費（或權利金）、對遊客徵收生態稅、乃至限制開放對象等等。最後，(4) 在內生決定經營業者家數的架構下，政府仍舊可以透過許可費（或權利金）的高低來左右廠商家數，以避免低均衡的出現。

This paper develops a theoretical model for the ecotourism industry with multi-firm to analyze the dynamic relation between the number of tourists and the stock of ecological resources under equilibrium. In addition, we analyze the regulation policies that can be effectively designed to avoid the situation of overexploitation of the natural resources under the development of ecotourism. Depending on how the firm numbers are determined, two cases will be considered, one with firm numbers directly controlled by the government, the other endogenously determined (or indirectly determined by other regulation policies). Based on the comparative statics analysis, it is shown that (i) there are two stable equilibria, one characterized by a lower level of the natural resource and the other by higher level. And, (ii) the reasons for leading to lower ecological stock (or called as overexploitation) aremainly due to too many operation firms and/or too many potential visitors along with the lack of quantity restriction. (iii) Thus, to escape from the overexploitation equilibrium, several polices can be adopted, such as increasing the license fee for operators, imposing the ecotourism tax on the tourists, and/or controlling the population of potential tourists. (iv) Finally, under the case of endogenous firm numbers, the government can affect the equilibrium number of firms by imposing a suitable level of license fee to avoid lower equilibrium.