The entropy function for five-dimensional supersymmetric black rings, which
are solutions of U(1)3 minimal supergravity, is calculated via both
on-shell and off-shell formalism. We find that at the tree level, the entropy
function obtained from both perspectives can reproduce the Bekenstein-Hawking
entropy. We also compute the higher order corrections to the entropy arising
form five-dimensional Gauss-Bonnet term as well as supersymmetric R2
completion respectively and compare the results with previous microscopic
calculations.Comment: 17 pages, no figure, JHEP3 style, to appear in JHEP