首先
在.NET的解决方案管理器中右键单击工程找到添加引用，在选项卡里选择COM   在列表里找到Excelxx（xx是版本号有9.0;10.0等,对了一定要先安装Excel啊,否则找不到的）,选择确定,然后就可以在你的程序中Excel.ApplicationClass了

string excelFilePath = @"C:\Inetpub\wwwroot\news\test.xls";
        Excel.Application myExcel = new Excel.ApplicationClass();
        object oMissing = System.Reflection.Missing.Value;
        myExcel.Application.Workbooks.Open(excelFilePath, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing);
        Excel.Workbook myBook = myExcel.Workbooks[1];
        Excel.Worksheet mySheet = (Excel.Worksheet)myBook.Worksheets[1];
        System.Data.DataTable dt = new System.Data.DataTable("mytable");
        dt.Columns.Add("F1", System.Type.GetType("System.String"));
        dt.Columns.Add("F2", System.Type.GetType("System.String"));
        dt.Columns.Add("F3", System.Type.GetType("System.String"));
        dt.Columns.Add("F4", System.Type.GetType("System.String"));
        dt.Columns.Add("F5", System.Type.GetType("System.String"));
        DataSet myDs = new DataSet();
        myDs.Tables.Add(dt);
        DataRow myRow;
        myDs.Clear();
        for (int i = 2; i <= 4; i++) //第一行为标题，不读取
        {
            myRow = myDs.Tables["mytable"].NewRow();
            for (int j = 1; j <= 5; j++)
            {
                Excel.Range r = (Excel.Range)mySheet.Cells[i, j];
                string strValue = r.Text.ToString();
                string aa = strValue;
                Response.Write("--"+aa+"--");