using System.Drawing.Printing.PrintDocument using System.Drawing.Printing.PrinterSettings.PaperSizeCollection using System.Drawing.Printing.PaperSize using System.Drawing.Printing.PageSettings /////////需要以上引用 PrintDocument pd = new PrintDocument(); PaperSize p=null; foreach(PaperSize ps in pd.PrinterSettings.PaperSizes) { if(ps.PaperName.Equals("A3")) p = ps; } pd.DefaultPageSettings.PaperSize = p; pd.Print();