Encased　CFST　(Concrete　Filled　Steel　Tubular)　arch　structure　is　an　innovative　arch　structure,　in　which　heavy　arch　lifting;　especially　in　long　span　arch　bridge　is　avoided　implementing　special　technique　in　its　construction,　as　in　construction　of　Wushan　Yangtze　River　Bridge　of　span　420　m.　With　the　attempt　to　compute　time　dependent　stresses　and　deformation　due　to　creep,　an　experimental　creep　study　is　organized　on　plain　concrete,　CFST　and　encased　CFST　column,　and　the　test　result　on　column　member　is　verified　using　numerical　method.　The　verified　numerical　technique　is　employed　to　compute　creep　effect　on　arch　bridges.