The management-retrieval code of the sub-library of atomic mass and characteristic constants for nuclear ground state (MCC) is used for displaying the basic information on the MCC sub-library on the screen, and retrieving the required data. The retrieved results are put into the data file OUTMCC.DAT. The code was finished at Chinese Nuclear Data Center (CNDC), and has widely been used in nuclear model calculations of nuclear da The management-retrieval code of the sub-library of atomic mass and characteristic constants for nuclear ground state (MCC) is used for displaying the basic information on the MCC sub-library on the screen, and retrieving the required data. put into the data file OUTMCC.DAT. The code was finished at Chinese Nuclear Data Center (CNDC), and has been been used in nuclear model calculations of nuclear da