"The South China Sea No.1" is the wreck of the longest,largest and most perfectly protected by now.It is a classical sample to study the craftwork of bireme and the technology of navigation.The relics loading on it may open out many secrets of" the Silk Road on the sea".So its archaeological value is much more than its economical value.In this paper,the concretion and corrosion on the surface of copper samples were obtained from "The South China Sea No.l".The samples were analyzed by many morden analysis technology,such as metallographic microscopy,3d video microscopy,X-ray diffraction(XRD),X-ray fluorescence(XRF),Scanning microscopy(SEM-EDS)and so on.The results show that the copper coin is tin-lead bronze,and the content of Cu is about 94%.The corrosion is mainly Cu2(OH)3Cl、 Cu2O、 Cu(OH)2 、Cu(OH)Cl、 Cu(SO4)2.The concretion is rich on the surface of copper coin,and the matrix turns thinner.The element of Pb is scattering freely in the matrix.Sn is high in the corrosion,which show that some Cu has corroded,The electrochemistry corrosion occurred was controlled by the Oxygen depolarization.The selective corrosion happed between Cu and Sn,and the effect of CI-is to speed up the rate of corrosion in the electrochemistry corrosion reaction..The achievements of the studies can provide references for the protection of the copper excavated from South China Sea.