Abstract: In order to study the mechanical properties of reinforced concrete short square-columns strengthened with prestressed CFRP sheets under axial compression,3 groups of RC square-columns,total of 12,were designed according to reinforcement ratio,each group including 3 RC columns strengthened with prestressed CFRP sheets and 1 RC column.The experimental data such as ultimate compressive bearing capacity,displacement and stress increment of prestressed CFRP sheets were obtained from the static load test.Load deformation curve and failure mode of specimens were also achieved.The effect of stress level of prestressed CFRP sheets and reinforcement ratio on the mechanical properties of strengthened RC short square-columns was analyzed.The experimental results indicated that strengthening with prestressed CFRP sheets could limit concrete lateral deformation,confine concrete by hoop stress from strengthening moment,as well as improve the ultimate compression strain of concrete,thus remarkably enhancing column ultimate bearing capacity by more than 60%.What's more,the ductility of compression columns strengthened with prestressed CFRP sheets was influenced by reinforcement ratio.When reinforcement ratio of the strengthened column was lower,ductility was better,otherwise worse.