  We study quantum corrections on four derivative term of vector multiplets in
${\cal{N}}=2$ supersymmetric Yang-Mills theory. We first show splitting of
quantum correction on gauge neutral hypermultiplets from U(1) vector multiplets
at four derivative order. We then revisit the non-renormalization theorem given
by N. Seiberg and M. Dine and show the non-renormalization theorem in mixed
(coulomb plus Higgs) branch even though gauge neutral hypermultiplet develops
the vacuum expectation value.
