Astrocytes play an important role in the formation of glial scars. in order to investigate the effect of inhibiting GFAP gene expression on normal, reactive astrocytes and on glial scar formation, the efficiency of the recombinant antisense GFAP retrovirus (PLBskG) on the growth, celi cycle, morphology and GFAP gene expression of astrocytes in vitro and on the formation of glial scars in vivo has been studied by celi growth curves, flow cytometry, immunocytochemistry, in situ hybridization, RT-PCR and Southern blot. The results confirm the recombinant retrovirus (PLBskG) produced growth suppression and G1 arrest of the normal and injured astrocytes. The infected cells become round or ellipoid. The celi processes become fine or retracted. The intensity of stain-ing of GFAP is reduced. Expression of GFAP mRNA is down regulated. However, in the control experiment, no obvious effects on the morphology or synthesis of GFAP on cultured normal and scratched astrocytes infected by primary retrovirus vector (PLX Astrocytes play an important role in the formation of glial scars. In order to investigate the effect of inhibiting GFAP gene expression on normal, reactive astrocytes and on glial scar formation, the efficiency of the recombinant antisense GFAP retrovirus (PLBskG) on the growth, celi cycle, morphology and GFAP gene expression of astrocytes in vitro and on the formation of glial scars in vivo has been studied by celi growth curves, flow cytometry, immunocytochemistry, in situ hybridization, RT-PCR and Southern blot. The results confirm the recombinant retrovirus The resulting cells become round or ellipoid. The intensity of the stain-ing GFAP is reduced. Expression of GFAP mRNA is down regulated (PLBskG) produced growth suppression and G1 arrest of the normal and injured astrocytes. However, in the control experiment, no obvious effects on the morphology or synthesis of GFAP on cultured normal and scratched astrocytes infected by primary retr ovirus vector (PLX