The plant expression vector of choleratoxin B subunit(CTB)-human insulin(BA) fusion protein pBI121/(CTB-BA) was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and its hypoglycemic effect was evaluated in mice. The plant expression vector pBI121/(CTB-BA) was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was transformed with previously constructed recombinant plasmid pBI121/(CTB-BA) via the freeze tha-wing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by co-culturing the cells with the transformed LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA se-quence assey and RT-PCR. The expressed product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice.The sequences of synthetic CTB and human insulin genes(BA) were completely identical to those designed. Restriction map proved that the length of gene fragment in-serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was consistent with that expected. The ex-pressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result.The animal test showed that only the G Penta-pyhllum Makino callus cell line itself showed activity in decreasing the blood sugar of mice, however, the activity of the transformed G Pentapyhllum Makino callus cells was much higher. The plant expression vector pBI121/(CTB-BA) was constructed and expressed in the G Pentapyhllum Makino callus cells successfully for the first time. The trans-formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This study developed a new way for the development of oral administration insulin. The plant expression vector of choleratoxin B subunit(CTB)-human insulin(BA) fusion protein pBI121/(CTB-BA) was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and Its hypoglycemic effect was evaluated in mice. The plant expression vector pBI121/(CTB-BA) was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was used with previously constructed recombinant plasmid pBI121/(CTB-BA) via the freeze tha- Wing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by coculturing the cells with the same LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA se-quence assey and RT-PCR. Product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice.The sequences of synthetic CTB and human insulin genes(BA) were comple Tely identical to those designed. Restriction map proved that the length of gene fragment in-serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was Consistent with that expected. The ex-pressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result. The animal test showed that only the G Penta-pyhllum Makino callus cell line’s excellent activity in reducing the blood sugar of mice, however, the activity of the blood G Pentapyhllum Makino callus cells was much higher. The plant expression vector pBI121/(CTB-BA) was constructed and expressed in The G Pentapyhllum Makino callus cells successfully for the first time. The trans-formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This stu dy developed a new way for the development of oral administration insulin.