A　large　number　of　previous　studies　have　demonstrated　that　visual　search　on　Web　pages　is　impacted　by　many　factors,　such　as　colors,　fonts,　information　forms　and　information　layout.　However,　there　are　few　studies　about　the　effect　of　information　quantity　for　visual　search　on　Web　pages.　To　investigate　this　issue,　we　designed　two　experiments　using　eye-tracking.　The　information　quantity　of　Web　pages　in　Experiment　2　was　the　double　of　that　in　Experiment　1.　Results　show　that　the　search　time　in　Experiment　2　is　significantly　longer　than　that　in　Experiment　1.　From　the　heat　maps　of　Experiment　2,　most　of　the　fixations　were　on　the　upper　area　of　Web　pages,　especially　on　the　upper　half.　Further　analysis　indicates　that　in　Experiment　2,　both　of　the　fixation　duration　and　fixation　count　on　the　upper　half　of　Web　pages　are　significantly　larger　than　that　on　the　lower　half.　These　results　suggest　that　the　increase　of　information　quantity　on　Web　pages　reduces　the　users＇　visual　search　efficiency　and　this　is　the　impact　of　information　overload　on　Web　pages.　The　reason　for　this　effect　is　that　the　range　of　the　users＇　vision　is　limited　and　they　pay　more　attention　to　the　upper　area　of　Web　page,　especially　the　upper　half.　©　2010　IEEE.