We have achieved successful transformation of Solanum dulcamara protoplasts by direct DNA uptake and regeneration of transgenic plants. The plasmids pDW2 carrying CAT gene and pCaMVNEO carrying NPTII gene were used. The electroporation voltage was 1500 V, which gave a field strength of 1500 V/cm with a time decay constant of 59.4 sec. The concentration of plasmid was 20 micrograms/2 x 10(6) protoplasts. Under these conditions, a very high transformation efficiency was obtained, with relative transformation frequency being up to 12.4% and absolute transformation frequency 2.4 x 10(-4). The activity of NPTII was detected in 75% of the kanamycin resistant calli and all of the plants regenerated from resistant calli. Southern blot analysis showed that the DNA sequence of NPTII gene derived from pCaMVNEO plasmid existed in the transformed plants of S. dulcamara.