Two selection systems for Agrobacterium tumefaciens mediated transformation of tomato and potato were compared. In the tomato (Lycopersicon esculentum cv. Moneymaker), the highest transformation rate, 4.2 %, of cotyledon explants on mannose-selection medium was obtained when mannose/sucrose concentration in the regeneration medium was 5/15 g dm-3. The best transformation efficacy with the commonly used concentration of 100 mg dm-3 kanamycin as a selection agent was 9 %. In the potato (Solanum tuberosum cv. Bintje), the highest transformation frequency was 53.3 % when mannose concentration in the regeneration medium was 5 g dm-3 during the first 3 weeks after transformation and 10 g dm-3 afterwards. The optimum concentration of sucrose was 20 g dm-3. The transformation efficiency using kanamycin as a selection agent at a concentration 100 mg dm-3 was 33.3 % with potato. Our results demonstrate that the transformation efficiency using mannose selection is 1.6-fold higher for potato and about 2 times lower for tomato comparing with the ordinary protocol using kanamycin.