Hi, I just found these in my website logs:

au _Australia 60.178.70.12 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:10:43
_au _Australia 60.178.70.153 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:10:11
_au _Australia 60.178.70.194 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:08:24
_au _Australia 60.178.70.87 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:07:28
_au _Australia 60.178.70.73 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:06:47
_au _Australia 60.178.70.10 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:06:03
_au _Australia 60.178.70.109 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:05:52
_au _Australia 60.178.70.140 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:05:44
_au _Australia 60.178.70.210 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:05:10
_au _Australia 60.178.70.100 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:03:07
_au _Australia 60.178.70.203 1 _Windows XP _Internet Explorer 6.0 2005-04-07 09:00:47
_au _Australia 60.178.70.197 1 _Windows XP _Internet Explorer 6.0 2005-04-07 08:59:48
_au _Australia 60.178.70.70

look at the IPs which start with 60.178.70.*, what did these IP want to do? they are trying to attack my website??? or something else. thanks

Look like some sort of spider from China. Maybe it's legit - some sort of SE spider. Maybe it's harvesting email addresses. You could just block 60.178.70.* if you're worried about it, or a quick search will reveal a number of methods for spider trapping you could use to handle this for you (for this IP and any other bots that are misbehaving).

Here's a nice list of bad bots to get you started :) - http://www.htmlhelp.com/.htaccess