Techniques were developed for embryogenic callus induction, transformation and regeneration of Sri Somrong 60, a Thai cotton variety. Somatic embryogenesis was obtained by culturing hypocotyl explants onto zeatin: NAA containing MS medium and subculturing onto hormone free transferring medium. This methods yielded 23.52-50% embryogenic callus induction. Transformation of Sri Somrong 60 with GUS gene and synthetic cryIA(b) gene was accomplished by using Aggrobacterium tumefaciens strain C 58 at 1150 dilution with the addition of 100 micronM acetosyringone to the medium during inoculation and incubation periods. Fragments of crylA(b) gene were amplified from DNA isolated from transformed calli and regenerated plants suggesting that transformation of Sri Somrong 60 with CryIA(b) gene was successful. (Résume d'auteur)