方法一：
打开
\ruby\lib\ruby\gems\1.8\gems\rails-1.2.5\lib\commands\servers\webrick.rb
rails-{ver}
ver是你当前的rails版本.
找到
OPTIONS = {
:port
=>
3000,
:ip
=>
"0.0.0.0",
:environment
=>
(ENV['RAILS_ENV'] || "development").dup,
:server_root
=>
File.expand_path(RAILS_ROOT + "/public/"),
:server_type
=>
WEBrick::SimpleServer,
:charset
=>
"UTF-8",
:mime_types
=>
WEBrick::HTTPUtils::DefaultMimeTypes
}
把 port 后面的3000修改成你想要的端口号.
方法二：
ruby script/server -p
3000
