Plant regeneration from cotylendon protoplasts of tomato (Lycopersicon esculentum cv. Kyoryokutoko) was obtained by somatic embryogenesis. Protoplasts were isolated from cotyledons of 8-10 day old in vitro-grown seedlings raised in a controlled chamber (20 °C, 3, 000-4, 500 lux, 16h). During initial protoplast culture, the addition of TM-2 medium (Shahin 1985) containing 0.15M sucrose, at 4 day intervals (sucrose concentrations were progressively reduced, 0.2M-0.17M-0.16M), resulted in vigorous cell divisions and prevented the browning of the cells. Somatic embryogenesis was induced from up to 50% of selected greenish calli when cultured on TM-4 medium supplemented with 2.0 mg/l zeatin riboside. Multiple adventitious shoots were formed by clonal propagation of somatic embryos on TM-4 or Murashige and Skoog (1962) medium containing 1.0 mg/l zeatin and 0.1 mg/l indoleacetic acid. Ninety-eight regenerated plants obtained from rooting shoots on Murashige and Skoog medium (0.8% agar, 20 g/l sucrose) were grown to maturity.