Hi Ahmed,

you can! The code will be something like this, depending on the Umbraco version you're working with:

// Umbraco 4
 DocumentType dt = DocumentType.MakeNew(new umbraco.BusinessLogic.User(0), "My New DocumentType");
 dt.Save();

 // Umbraco 6
 var cs = ApplicationContext.Current.Services.ContentTypeService;
ContentType ct = new ContentType(-1);
 ct.Name = "My New v6 DocType"; ct.Alias = "myNewV6Doctype";
cs.Save(ct);

 About the Umbraco 6-code I'm not 100 percent sure, but it's something like that.

Cheers, Jeffrey