楊氏海源閣爲清末四大藏書樓之一，其最鼎盛之際曾使海内珍善本集聚海 源閣，與瞿氏鐵琴銅劍樓並稱「南瞿北楊」。在其豐富的藏書中，最另人稱道 的爲宋版四經四史，更另闢專室以藏之，名爲「四經四史之齋」。本文除略述 楊氏海源閣藏書之來龍去脈，並介紹其鎮閣之寶四經四史。

Hai Yuan Ge is one of the four important private bibliotheca in late Chifng Dynasty. In its heyday, it collects the most important woodblock printing books in China. Among its abundant collections, the most highly valued books are Si Jing Si Shi: four classic books of Confucian canon and four books of Chinese history printed in Sung Dynasty. The purpose of this paper is to introduce Hai Yuan Ge, and its exquisite collection: Si Jing Si Shi.