Abstract: Carbon fiber reinforced polymer (CFRP) composite is a new high-performance material with the advantages of light weight, high strength and corrosion resistance. This paper presents the results of experimental studied on the size effect of the eccentric compressive performance of reinforced concrete columns strengthened with CFRP composite sheets. A total of fifteen reinforced concrete columns were designed and tested up to failure under eccentric compressive loads, the columns were geometrically similar to one another. Three factors were taken into consideration in this study, such as the size of column, eccentricity and the layers of CFRP composite sheets. The test results indicate that the failure modes, the relative deflection, the peak strains of CFRP composite and steels are obviously affected by the size of columns. The ultimate load of reinforced concrete columns strengthened with CFRP composite sheets significantly decreases with the eccentricity increases, and the rate of decrease gradually becomes slower with the size increasing. Under the same eccentricity, the safety storage coefficient of reinforced concrete columns strengthened with CFRP composite gradually decreases with the increase of the size.