The silver-sheath technique is most powerful for preparing the high Tc superconducting tapes. It comprises a serial step of handlings. A general feature of this process is firstly introduced. The recent developments of Y123, Y124, Bi2212, Bi2223 and T1 oxide tapes have been reviewed. Problems which should be solved for the present technique and a future scope are discussed. Fundamental investigations are emphasized to be still very important in this scientific field.