McAb CC-1 (IgM) could react with 45％ of the human colon carcinomas, its antigenic determinant is extended LeY~1 Our purpose of producing CC-1 second generation McAbs is to select more effective McAbs in clinical application, and to find out the structure and excretion of glycolipid antigen so as to understand the mechanism of originality and development of tumors? McAb CC-1 (IgM) could react with 45% of the human colon carcinomas, its antigenic determinant is extended LeY ~ 1 Our purpose of producing CC-1 second generation McAbs is to select more effective McAbs in clinical application, and to find out the structure and excretion of glycolipid antigen so as to understand the mechanism of originality and development of tumors?