Many　studies　on　size　effect　of　quasi-brittle　materials　such　as　concrete　and　mortar　have　been　carried　out.　But　experimental　study　and　theoretical　analysis　combining　with　concrete　structure　or　component　is　not　sufficient,　and　related　theory　is　not　verified　fully.　This　paper　collects　test　information　of　five　different　section　size　samples　in　different　loading　stage,　including　bearing　capacity,　deflection,　section　strain　and　so　on.　The　total　number　of　specimens　is　13.　This　can　help　to　revise　related　design　theories.　The　safety　of　related　bearing　capacity　formula　is　verified　in　research　scale,　but　safety　reserve　of　calculation　theory　shows　a　trend　of　decrease　with　specimen　dimension　increasing.　As　for　large-size　bending　specimens,　size　effect　of　concrete　material　is　reflected　in　mechanical　properties　of　reinforced　concrete　structures,　the　code　value　of　ultimate　strain　under　non-uniform　compression　is　bigger　than　test　value.　It　is　also　found　that　size　affect　of　components　have　more　influence　on　beam　than　size　affect　of　concrete　materials.　©　2011　IEEE.