在目前3D虛擬環境中，虛擬人物的動作多半是以動作抓取等離線方式錄製後，再以罐裝動作的方式呈現。該動作經過編碼後會以固定的格式進行傳送，然後由客戶端撥放該動畫內容。通常而言，固定的格式規範會限制電腦動畫表現與延展的能力。這篇論文我們提出了一套以XML為基礎的動畫語言，稱為eXtensible Animation Markup Language(XAML)來解決這樣的問題。這套語言設計的目的是為了讓開發者能夠彈性地選擇不同層次的指定方式來產生虛擬演員的動畫；同時使用者可以藉由已經定義好的動畫合成新的動畫內容，或是更改已定義動畫的部分內容來產生一套新的動畫。除此之外，XAML為客製化腳本語言提供延展擴充的機制，開發者可以透過plug-in、內嵌XAML引擎或轉換腳本等方式達到擴充XAML的目的。我們同時使用JAVA實作了一套能夠解譯XAML的動畫引擎，使用者不但可以利用XAML腳本命令產生相對應的3D動畫顯示，也可以透過該動畫引擎所提供的函式庫對場景中的3D物件進行控制。另外，我們也設計了一個具語音對話功能的多人虛擬環境系統，以驗證XAML語言的可行性及有效性。 / Character animations on most virtual environment systems are canned motions created off-line through motion capture techniques. The motions are then en-coded and transmitted with a fixed format and played at the client side. The rigid specification format for computer animation and multimedia presentation in general has greatly affected the development of 3D contents. In this thesis, we propose an XML-based scripting language, called eXtensible Animation Markup Language (XAML). The language is designed to describe character animations at various command levels and to compose a new animation from existing ani-mation clips. Furthermore, one can use plug-in, embeding or translation to in-corporate other customized scripting languages or new functions into XAML. We have implemented an animation engine in Java that can interpret the script-ing language and render 3D animations based on the user’s interactive XAML commands or the provided application programming interface. In addition, we have designed a speech-enabled multi-user virtual environment system based on XAML to verify the feasibility and effectiveness of such a language.