Abstract: SPF SCID mice breeding colony has been maintained successfully in the barrier sys-tem. The reproductive performances and growth of SCID mice were observed. The results showed that the weaning litter sizes were 3. 8±1.3（1♂×1♀）and 4.4±1.6（1♂×2♀），life spans were over 12 months. The microbiological quality monitoring showed that the SCID mice were specific pathogens free. The human tumor cells,including lung cancer （H128）,stomach adenocarcinoma （SGC-7901），brain cancer （U251） and hepatocellular carcinoma （BEL-7402,SMMC-7721），were transplanted successfully onto these SCID mice.The results showed that the human tumor grew much better in SCID mice as compared with those in BALB/c -nu mice. Moreover, metastasis were observed in SCID mice with SMMC-7721 and SGC-7901 transplantaion，especially the later with a high metastatic rate in the liver,lymph node，peritoneum and spleen.