You can use something like this.. you need have oledb drive on your server.
    String sConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + uploadFilenm + "; Extended Properties=" + (char)34 + "Excel 8.0;IMEX=1;" + (char)34;
   // Create connection object by using the preceding connection string.
    OleDbConnection objConn = new OleDbConnection(sConnectionString);
    // Open connection with the database.
    objConn.Open();
    // The code to follow uses a SQL SELECT command to display the data from the worksheet.
    // Create new OleDbCommand to return data from worksheet.
    OleDbCommand objCmdSelect = new OleDbCommand("SELECT * FROM [sheet1$]", objConn);
    // Create new OleDbDataAdapter that is used to build a DataSet
    // based on the preceding SQL SELECT statement.
    OleDbDataAdapter objAdapter1 = new OleDbDataAdapter();
    // Pass the Select command to the adapter.
    objAdapter1.SelectCommand = objCmdSelect;
    // Create new DataSet to hold information from the worksheet.
    DataSet objDataset1 = new DataSet();
    // Fill the DataSet with the information from the worksheet.
    objAdapter1.Fill(objDataset1, "XLData");