臺灣菸品市場之租稅負擔是個很奇特之現象，當臺灣政府對香菸產品課稅時，菸商會將租稅完全轉嫁給消費者，即便消費者之需求是有彈性的。本文為探討此原因，以Milgrom and Roberts之利潤目標模型為基礎，建立一個廠商追求利潤目標之模型來解釋，當菸商面臨政府課稅時，是否會將租稅百分之百轉嫁給消費者。由此模型推論出，若菸商欲維持市場之獨占或寡占地位時，便會追求較低之利潤目標，使潛在競爭者相信菸品市場利潤不大，此時潛在競爭者便不會進入菸品市場中與現有之菸商競爭。 本文設定利潤模型後，便以此利潤模型進行比較靜態分析，本文假設當菸商欲維持在市場之獨占或寡占地位時，於政府課徵從量稅後，會如何轉嫁租稅給消費者，並分別由價格及數量為切入點分析。經過比較分析後的結果可得知，只要菸商之目標為持續保有獨占或寡占之地位，而非追求利潤極大化時，租稅的完全轉嫁即會存在，即使消費者需求是有彈性的，消費者將會面對一個稅額百分之百增加的供給價格。 / The tax burden of cigarette products in the Taiwanese market baffles many researchers in public finance. Despite that the demand of cigarette products is elastic, when the tax rate of cigarette products increases, cigarette manufacturers, with no exception, raise the prices accordingly, and therefore, the increased taxes are entirely shifted to consumers. This is very different from the traditional idea of tax incidence based on elasticity. In order to figure out the reason, this paper uses the framework of the limit pricing model of Milgrom and Roberts (1982) with the assumption of target profit to establish an economic reasoning of why the tax hikes in the cigarette products are one hundred percent shifted to consumers. This model infers that when cigarette manufacturers have entry deterrence in mind, they tend to pursue a lower profit target to keep potential competitors away. Given the framework and basic assumption from above, comparative statics of tax increases are done for both quantity and pricing games. The results suggest that when cigarette manufacturers are facing an increase in the unit tax rate of their products, it is typical that the incidence of the increased tax been no less than one hundred percent forward-shifted to consumers. The traditional theory of tax incidence by elasticity under the profit maximization firms does not apply here. The economic intuition is that in order to thwart entry, existing firms use the complete forward shifting of the tax increase as a bad signal of the profitability of the market to potential competitors.