Somatic embryo tissues of Astragalus chrysochlorus were transformed with the beta-glucuronidase (GUS) and neomycin phosphotransferase II (npt II) genes by electroporation. The effect of electric field strength was tested for transient expression. It was found that 1000 V/cm and 200 mu s and 1 pulse was the optimum combination to transform embryo tissues (expression level was 61.5%). Electroporated somatic embryo tissues were positive for GUS expression and PCR analysis for the genes GUS and npt II. After PCR analysis, we found that the efficiency of the somatic embryos with transient GUS expression by electroporation was 48%.