I want to know whether there is solaris 10 64bit for X86_64. But when I searched it in Google, I just finded solaris 10 32bit for X86_64. Could someone tell me if SUN supplies solaris 10 64bit for X86_64?

yes http://partneradvantage.sun.com/pro... only if Intel® EM64T requires a computer system with a processor, chipset, BIOS, operating system, device drivers and applications enabled for Intel EM64T. Processor will not operate (including 32-bit operation) without an Intel EM64T-enabled BIOS. Performance will vary depending on your hardware and software configurations. See http://www.intel.com/info/em64t for more information including details on which processors support Intel® EM64T or consult with your system vendor for more information. I read it wrong and answer it wrong too. So get off my case you peanut.