Q: Mac OS X startup fail.. only apple logo shows.. please help me.. i havnt OS X Disc..

You need either the disks that shipped with your Mac, or an external clone of your system because you will need DIsk Utility to try to fix.

Contact Apple, give them your serial number and they will send the disks for a nominal fee.

What system are the Disks?

If DU from the disks can't repair them, it may because it is an old DU. In that case your only option may be to reformat the disk and install the OS on your DVD, then upgrade to Lion by re-downloading the installer from MAS.

After that, you should be able to migrate from your backup.

EDIT: Also, what type of backup is it...TM, or clone?

Try a restart and hold down the "option" key untill you see the icon fo your HD. Clk on the arrow below the icon. If this works, when the computre is up, go to System Preferences/Startup Disk and select the HD that contains your boot system.

Step by Step to fix your Mac