Abstract: Transgenic plants were regenerated from soybean ( Glycine max (L.) Merr. ) immature cotyledons bombarded by gene-gun with plasmid pGB14AB which contained Bacillus thuringiensis Berliner insecticidal crystal protein gene (Bt gene )and GUS gene, and from cotyledon nodes infected with LBA4404 which contained pGB14AB. Immature cotyledons of "Zhonghuang No. 4' (variety) and 8502 (line) differentiated many more somatic embryos than others. Desiccation treatment of somatic embryos from immature cotyledons of "Zhonghuang No. 4" improved significantly their germination frequency. Preculturing of immature cotyledon was beneficial for somatic embryogenesis from the cotyledons infected with Agrobacterium tumefaciens (Smith et Townsend) Conn. High efficiency of transformation is related to selection of genotype and recipient, desiccation treatment of somatic embryos and improvement of transformed system in soybean.

Key words: Bt gene, GUS gene, Gene-gtm bombard, Agrobacterium-mediated transformation, Soybean transgenic plant