在這篇論文裡，我們探討卡塔蘭等式 (n + 2)Cn+1 = (4n + 2)C2 的證明 方法。以往都是用計算的方式來呈現卡塔蘭等式的由來，但我們選擇用組合 的方法來證明卡塔蘭等式。 這篇論文主要是應用 Cn+1 壞路徑對應到打點 Cn 好路徑以及 Cn+1 好路 徑對應到打點 Cn 壞路徑的⽅式來證明卡特蘭等式。 / In this thesis, we give another approach to prove Catalan identity, (n + 2)Cn+1 = (4n + 2)C2. In the past we use the method of computation to show Catalan Identity, in this thesis we choose a combinatorial proof of the Catalan identity. This thesis is primary using the functions from Cn+1 totally bad path to Cn dotted good path, and from Cn+1 good path to Cn dotted totally bad path.