Creating content types programmatically

public static void createContentTypes()

        {

            string contentTypename = "My Content Type";

            try

            {

                SPSecurity.RunWithElevatedPrivileges(delegate()

                {

                    using (SPSite osite = newSPSite("http://myserver03:7676/abc"))

                    {

                        using (SPWeb oweb = osite.OpenWeb())

                        {

                            SPContentType contentType = newSPContentType(oweb.ContentTypes["Document"], oweb.ContentTypes, contentTypename);

                            oweb.ContentTypes.Add(contentType);

                            contentType.Group = "Custom Content Types";

                            contentType.Description = "Custom content type";

                            Console.WriteLine("Content Type Created");

                            Console.ReadLine();

                        }

                    }

                });

            }

            catch (Exception ex)

            {

                throw ex;

            }

 

        }

Note : If you need to add columns to content types programmatically,please check out my blog.I have a post on how to add columns programmatically.