Require following ftp details where you want to upload the files:

FTP URL: “ftp://ftp.yoursite.com/”
FTP Username: username
FTP Password: password
FTP Port: 21

Upload File


public string UploadFile(string FtpUrl, string fileName, string userName, string password, string UploadDirectory = "")
        {
            string PureFileName = new FileInfo(fileName).Name;
            String uploadUrl = String.Format("{0}{1}/{2}", FtpUrl, UploadDirectory, PureFileName);
            FtpWebRequest req = (FtpWebRequest)FtpWebRequest.Create(uploadUrl);
            req.Proxy = null;
            req.Method = WebRequestMethods.Ftp.UploadFile;
            req.Credentials = new NetworkCredential(userName, password);
            req.UseBinary = true;
            req.UsePassive = true;
            byte[] data = File.ReadAllBytes(fileName);
            req.ContentLength = data.Length;
            Stream stream = req.GetRequestStream();
            stream.Write(data, 0, data.Length);
            stream.Close();
            FtpWebResponse res = (FtpWebResponse)req.GetResponse();
            return res.StatusDescription;
        }

Download File


 public static string DownloadFile(string FtpUrl,string FileNameToDownload,
                        string userName, string password,string tempDirPath)
    {
        string ResponseDescription = "";
        string PureFileName = new FileInfo(FileNameToDownload).Name;
        string DownloadedFilePath  =  tempDirPath+"/"+PureFileName;
        string downloadUrl = String.Format("{0}/{1}", FtpUrl, FileNameToDownload);
        FtpWebRequest req = (FtpWebRequest)FtpWebRequest.Create(downloadUrl);
        req.Method = WebRequestMethods.Ftp.DownloadFile;
        req.Credentials = new NetworkCredential(userName, password);
        req.UseBinary = true;
        req.Proxy = null;
        try
        {
            FtpWebResponse response = (FtpWebResponse)req.GetResponse();
            Stream stream = response.GetResponseStream();
            byte[] buffer = new byte[2048];
            FileStream fs = new FileStream(DownloadedFilePath, FileMode.Create);
            int ReadCount = stream.Read(buffer, 0, buffer.Length);
            while (ReadCount > 0)
            {
                fs.Write(buffer, 0, ReadCount);
                ReadCount = stream.Read(buffer, 0, buffer.Length);
            }
            ResponseDescription = response.StatusDescription;
            fs.Close();
            stream.Close();
        }
        catch(Exception e)
        {
            Console.WriteLine(e.Message);
        }
        return ResponseDescription;
    }