my configration ::: aphache 2 + php 5.0.1
i have download the dbg-cli and php_dbg.dll . in my phpini.
php_dbg.dll is added . in phpinfo() it can display the dbg information well.
dbg-cli.exe can run well .

but how can i display the debug information?
i have tried the debugger_on(localhost). but it 's only used in php3.it can 't display any debug information.

did you read dbg-cli readme ?
did you run help command in dbg-cli console ?
Please note that the latest dbg-cli (2.11.30) is suitable for Linux/Unix platforms only. As for Windows, you'd try an IDE that works through dbglistener.