Thank you for your comment. But using GDI+, when you draw a text on transparnet background and save the image you will see that the font smoothing is completely good. It seems here font smoothing take place by Mixing Font color with Transparent color, using Alpha value in ARGB. Also Applications like Photoshop do the job well. So there should be a win32(GDI)approach to drawing smooth text on transparent bitmaps. in GDI+ the code is like to this: Bitmap myBitmap=new Bitmap(100,100,Format32bppArgb); Graphic g=Graphics.FromImage(myBitmap); g.DrawString("Test", Font, Brushes.Black, 0, 0); myBitmap.Save("myBitmap.png",ImageFormat.Png);