yes - Mountain Lion System Requirements - http://support.apple.com/kb/HT5444.
Also, make sure that your computer can in fact be upgraded to the newer OS version. Check your computers model and year - https://selfsolve.apple.com/agreementWarrantyDynamic.do.
Once you know the model and year, ensure that your model is supported for the 10.8 OS - http://www.apple.com/osx/specs/.
Also remember to ensure that all your other applications are supported by the new OS - http://www.roaringapps.com.
If needed - Lion System System Requirements - Mac OS X 10.7 Lion System Requirements