《合同法》230条规定的承租人优先购买权制度是一项重要制度。现在学界大多数学者认可该权利性质为形成权。在承租人作出优先购买的意思表示时,在出租人与第三人、出租人与承租人之间分别形成内容相同的买卖合同。由于最终只有一个合同能够履行,这不可避免地涉及到优先购买权对第三人的效力问题。本文便对承租人优先购买权的对抗效力作初步探究。 The tenant preemption system stipulated in Article 230 of the Contract Law is an important system. Now most academic scholars agree that the nature of the right to form the right. When the lessee makes the meaning of the priority purchase, the seller and the third party, the lessor and the lessee respectively form the same sales contract. As only one contract can be fulfilled in the end, it inevitably involves the question of the effectiveness of the preemptive right over the third party. This article will make a preliminary inquiry into the effectiveness of the lessee’s right of preemption.