This　paper　presents　a　comparative　study　of　the　influence　of　different　possible　residuals　in　objective　function　for　FEM　updating.　A　simulated　simply　supported　beam　without　damage　and　with　several　assumed　damage　elements　is　considered.　Four　different　cases　of　objective　function　consisting　of　frequency　residual　only,　mode　shape　related　function　only,　flexibility　residual　only　and　their　combination　are　studied　independently,　each　having　three　cases　depending　upon　the　number　of　updating　parameters.　It　is　observed　that　as　the　number　of　updating　parameter　in　the　FE　model　goes　on　increasing,　the　ability　of　optimization　algorithm　to　tune　the　frequency　and　MAC　value　goes　on　decreasing.　An　accurate　identification　of　damage　location　and　severity　becomes　difficult　if　a　large　number　of　parameters　and　elements　are　selected.　In　view　of　tuning　as　well　as　damage　detection,　objective　function　considering　frequency　and　MAC　related　residual　with　flexibility　residual　is　the　best　for　FEM　updating.