Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
pdfDoc.Open();
using (MemoryStream stream = new MemoryStream())
{
Chart1.SaveImage(stream, ChartImageFormat.Png);
iTextSharp.text.Image chartImage = iTextSharp.text.Image.GetInstance(stream.GetBuffer());
chartImage.ScalePercent(75f);
pdfDoc.Add(chartImage);
pdfDoc.Close();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=Chart.pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Write(pdfDoc);
Response.End();