首先引入类库，Microsoft.Office.Interop.Word,然后进行编程。代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Microsoft.Office.Interop.Word;

namespace WordTest
{
    public partial class Form1 : Form
    {
        object strFileName;
        Object Nothing;
        Microsoft.Office.Interop.Word.Application myWordApp = new Microsoft.Office.Interop.Word.ApplicationClass();
        Document myWordDoc;
        string strContent = "";

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            createWord();      
            //openWord();
        }

        private void createWord()
        {
            strFileName = System.Windows.Forms.Application.StartupPath + "test.doc";
            if (System.IO.File.Exists((string)strFileName))
                System.IO.File.Delete((string)strFileName);
            Object Nothing = System.Reflection.Missing.Value;
            myWordDoc = myWordApp.Documents.Add(ref Nothing, ref Nothing, ref Nothing, ref Nothing);

            #region 将数据库中读取得数据写入到word文件中

            strContent = "你好\n\n\r";
            myWordDoc.Paragraphs.Last.Range.Text = strContent;

            strContent = "这是测试程序";
            myWordDoc.Paragraphs.Last.Range.Text = strContent;

            #endregion

            //将WordDoc文档对象的内容保存为DOC文档
            myWordDoc.SaveAs(ref strFileName, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing, ref Nothing);
            //关闭WordDoc文档对象
            myWordDoc.Close(ref Nothing, ref Nothing, ref Nothing);
            //关闭WordApp组件对象
            myWordApp.Quit(ref Nothing, ref Nothing, ref Nothing);

            this.richTextBox1.Text = strFileName + "\r\n" + "创建成功";

        }
        private void openWord()
        {
            fontDialog1.ShowDialog();
            System.Drawing.Font font = fontDialog1.Font;
            object filepath = "D:\\asp.docx";
            object oMissing = System.Reflection.Missing.Value;
            myWordDoc = myWordApp.Documents.Open(ref filepath, ref oMissing, ref oMissing, ref oMissing, ref oMissing,
                ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing,
                ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing);
            myWordDoc.Content.Font.Size = font.Size;
            myWordDoc.Content.Font.Name = font.Name;
            myWordDoc.Save();
            richTextBox1.Text = myWordDoc.Content.Text;
           
           
            myWordDoc.Close(ref oMissing, ref oMissing, ref oMissing);
            myWordApp.Quit(ref oMissing, ref oMissing, ref oMissing);
        }

}

http://www.cnblogs.com/wrtandy/archive/2006/12/13/andy.html