The plasmid pGL2Rz including ribozyme gene was linearized and introduced into early eggs of silkworm (G(0)) by gene gun. The luciferase activity in blood of the G(1) generation was detected, then the resistant silkworm was selected by NPV infection from G(2) generation. The transgenic silkworm resistant against NPV 10 times more than control ones was got at the G(4) generation. PCR and Southern blotting proved that the ribozyme gene was integrated into the genome of silkworm multicopily. The expression of ribozyme was also detected by RT-PCR in pupa. The results showed that the transgenic silkworm strain of anti-NPV ribozyme has been got.