Central to the research of Chinese imperial rituals is the study of the Imperial Temple and Temple sacrifices. Among various Temple sacrifices, the evolution of seasonal sacrifices and sacrificial offerings had received adequate attention from ritual officials in imperial China. Historians have analyzed the transition of sacrificial offerings from the Tang dynasty (618-907) to the Northern Song dynasty (960-1127) in details. With a focus on several critical eras of Northern Song, this article aims to reveal how Northern Song ritual officials and their discussions about seasonal sacrifices in the Imperial Temple re-conceptualized the very nature of imperial rituals. Additionally, through a detailed analysis of the opinions of ritual officials who served in Emperor Shenzong's (r. 1067-1085) ritual bureaus and based on a newly discovered collected work of one of these officials, this article offers a more comprehensive picture of Song ritualism. Thus, it contributes to a new perspective to rethink Song imperial rituals and traditional ritual learning in relation to these rituals.