漢武帝罷黜百家，獨尊儒術。漢武帝所尊儒術其實就是《 春秋公羊傳》。緣由爲何？ 一般都認爲是《公羊傳》主張大一 統、尊王攘夷、君尊臣卑等政治思想$符合了西漢帝國體制維 繫的需要。本文證明《公羊傳》所提出的崇讓觀也有同樣的作 用。《公羊傳》所提倡的讓不是讓賢的襌讓，而是讓嫡長子繼 承君位的讓。西漢初期諸侯王所占據的版圖，遠超過中央。他 們出身編户齊民家族$缺乏西周氏族社會中的親親意識，因之 不但不能像西周封建諸侯那般衷心全力屏蕃中央，反而時時覬 覦天子之立。漢初政局由是十分不穩。《公羊傳》藉孔子之權 咸肯定了嫡長子繼承制，並藉孔子之口一再稱許了隱公等人的 讓國事蹟。《公羊傳》崇讓觀的提由因之深具時代意義。《公 羊傳》所以成爲西漢立國大法，這也是原因之一。

Why did the Kung-yang commentary of the Spring and Autumn Annals become the most dominant Scripture in the Emperor Wu reign of the West Han Dynasty? The general theory is that the scripture proposed a system of political ethics that perfectly met the ideological needs of the empire. This paper examines a particular concept in the scripture, (^), to substantialize the above theory. The concept of jang advocated by the scripture means to abdicate the throne to the eldest son of the principal wife (嫡長子）of the emperor, which is quite different from the traditional Confucian ideal of shang-jang (), that is, to abdicate the throne to the most worthy man (讓賢)• The reason for the commentary to propose the new concept of jang can be found by examining closely the political system and especially the mentality of the local kings of the formative period of the Western Han Dynasty. The significance of the concept jang can thus be revealed.