根據主持者的不同，郊祀禮儀有皇帝親祭與有司攝事兩種形式，原先這兩種形式的差別比較有限，但是從唐玄宗統治時期開始，兩者之間的差異不斷擴大。本文主要通過分析唐至北宋時期這些差異的形成過程，來探討皇帝親郊的歷史變遷。天寶以後，在南郊親祭前的兩天，皇帝分別前往太清宮和太廟舉行祭祀，因此合稱三大禮。五代和宋初皇帝在南郊親祭前只舉行太廟祭祀，但是隨著宋真宗時期景靈宮祭祀的出現，景靈宮、太廟和南郊祭祀構成新的三大禮。因為皇帝親郊祭祀性和非祭祀性的事務繁多，經過晚唐五代的醞釀，到了北宋初年，朝廷設立了大禮五使以負責各項事務。非祭祀性因素的成長是唐至北宋皇帝親郊最引人注目的變化。每逢皇帝親郊，地方官府和蕃夷都會前來助祭。親郊大赦儀式化，赦文的內容更趨豐富，不但包括各種赦免和賞賜，還成為立法的重要形式。臣下還通過多種儀式向皇帝進賀親郊成功舉行。這些非祭祀性因素的凸顯，意味著皇帝親郊比以前承載了更多的功能，它不僅僅用來確認和強化天子與神靈的關係，還成為展現人間秩序的舞臺。

This essay discusses the evolution of suburban sacrifices hosted by emperors or relevant bureaucrats, which had evolved into two distinct forms by the reign of Tang Xuanzong. Beginning from the Tianbao period, emperors held sacrifices in the Taiqing Temple and the ancestral temple respectively in the two days preceding the southern suburban sacrifices. These sacrifices in the Taiqing Temple, the ancestral temple and the southern suburbs were collectively called the “Three Grand Rites”. While during the Five Dynasties and the first years of the Northern Song Dynasty emperors had only conducted sacrifices in the ancestral temple before the southern suburban sacrifices by the reign of Song Zhenzong, the new “Three Grand Rites” were established, with the emergence of the sacrifice at Jingling Temple. Due to the complicated nature of the sacrifices, the Five Envoys of Grand Rites, originating in the late Tang, were established in the Five Dynasties. The most conspicuous change in the sacrifices was the rise of non-sacrificial affairs such as tributes presented to emperors by representatives of local governments and foreign regimes, and the ritualization and legislation of amnesties of the sacrifices including many remits and rewards. In addition, officials held congratulation rituals on the success of the sacrifices. The rise of non-sacrificial elements indicates the suburban sacrifices were not only used to confirm and strengthen the relationship between the Sons of Heaven and other deities, but were also a stage symbolizing interpersonal relationships.