一般圖書館查詢系統只能依靠關鍵字詞逐一尋找所需圖書，若遇到書名用詞或語言不同情況，就會增加找到符合需求圖書的困難度。本文推薦系統有別於一般關鍵字搜尋，希望能利用同儕借閱紀錄做協同推薦且使用圖書分類號輔助推薦排序。另外，由於個資問題，可能無法取得當下借閱者過去借閱紀錄，因此在不能直接使用人推薦物方法前提下，本文提出一套方法可同時適用於物推薦物及人推薦物之場合進行圖書推薦。 為輔助評估，本文使用機器學習軟體-Mahout的三種人推薦物方法，分別為斜率1、用戶為本和物品為本。此外本文也針對四種物推薦物方法進行比較，分別是本文提出的兩層關聯式物推薦物方法、Mahout物推薦物方法、兩層關聯式物推薦物結合分類號方法、不含本身兩層關聯式物推薦物結合分類號方法。本文以精確率為評估指標，結果發現本文提出方法優於Mahout三種方法，結合分類號比未結合佳，推薦時含給定圖書本身比不含佳。 Most library search systems only rely on keywords input by the user to find the desired books. When there are alternative synonyms or translations for the input keywords, one would often find it difficult to locate other related books. Instead of using the keywords approach, this work considers the use of collaborative filtering on the library circulation data for book borrowing recommendation. Under the premise that a user might not be willing to disclose the past borrowing records for privacy reasons, an item-based recommendation framework is proposed which will work for both use cases of item-based and user-based book recommendation. Given a book item, our two-layer relational item-based recommendation method will consider those books borrowed by the common users and use sorting keys first based on the past borrowing count and then on the call-number-based distance. For benchmarking, the Mahout open source machine learning package is adopted where the slope-one, user-based, and item-based recommendation methods are evaluated. In addition, four item-based recommendation methods are evaluated which include our two-layer relational item-based method, Mahout item-based method, our two-layer relational item-based method combined with the call number, and our two-layer relational item-based method excluding self recommendation. This work uses the precision as the performance index. The experimental results show that our method is better than the three Mahout methods. Our method combined with the call number is better than that without the call number. Also, our method with self recommendation is better than that without self recommendation too.