The　security　of　a　secure　quantum　sealed-bid　auction　protocol　using　quantum　secure　direct　communication　based　on　GHZ　states　[M.　Naseri,　Opt.　Commun.　282　(2009)　1939]　is　reexamined.　It　is　shown　that　the　protocol　does　not　complete　the　task　of　a　sealed-bid　auction　fairly.　It　is　shown　that　a　dishonest　bidder　can　obtain　all　the　other　one＇s　secret　bids　by　two　special　types　of　attack,　i.e.,　double　Controlled　NOT　attack　or　using　fake　entangled　particles.　Furthermore,　a　simple　possible　improvement　of　the　protocol　is　proposed.　(C)　2009　Elsevier　B.V.　All　rights　reserved.