protected void Button1_Click(object sender, EventArgs e)
    {
StrName = FileUpload1.PostedFile.FileName;//here we are taking the excel file ex: emp.xls
               DataTable myData = default(DataTable);
                myData = GetDataFromExcel(StrName, "Sheet1$").Tables[0];
                GridView1.DataSource = myData.DefaultView;
                GridView1.DataBind();
}
 

public System.Data.DataSet GetDataFromExcel(string FileName, string RangeName)
    {
        try
        {
            string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + FileName + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\""; 
            //here HDR means Header, if it "Yes" int incluedes Header if it is "No" it will come with out Headers

            System.Data.OleDb.OleDbConnection objConn = new System.Data.OleDb.OleDbConnection(strConn);
            objConn.Open();

            System.Data.OleDb.OleDbCommand objCmd = new System.Data.OleDb.OleDbCommand("SELECT * FROM [Sheet1$]", objConn);
            System.Data.OleDb.OleDbDataAdapter objDA = new System.Data.OleDb.OleDbDataAdapter();
            objDA.SelectCommand = objCmd;

            // Fill DataSet
            System.Data.DataSet objDS = new System.Data.DataSet();
            objDA.Fill(objDS);

            objCmd.Connection = objConn;
            using (OleDbDataReader dr = objCmd.ExecuteReader())
            {
               
                string sqlConnectionString = "server=SeverName;Initial Catalog=Testing;uid=sa;pwd=**;";
                // Bulk Copy to SQL Server
                using (SqlBulkCopy bc = new SqlBulkCopy(sqlConnectionString))
                {
                    bc.DestinationTableName = "emp";
                    bc.WriteToServer(dr);
                }

            }
            objConn.Close();
            return objDS;
        }
        catch
        {
            return null;
        }
    }