The effects of cold treatment (4°C for 0, 2, and 5 days), heat shock (30°C for 0, 2, and 5 days), and two induction media (B5 and NLN) supplemented with 2% and 9% sucrose were assessed on microspore embryogenesis induction in tomato using shed microspore culture technique. Significantly higher callusing was obtained when anthers were cultured on the B5 medium with 2.0 mg l-¹ 2, 4-D and 2.0 mg l-¹ BAP. In addition, IAA at 0.5 mg l-¹ in combination with 0.5 mg l-¹ Kin also substantially improved callogenesis. Chitosan treatment proved to be beneficial to callusing and shoot regeneration so that, high callogenesis (85%) and shoot regeneration (3%) was obtained from anthers treated with 50 mg l-¹ chitosan. Microspore-derived structures with more than 9 nuclei were observed in both media containing 2% sucrose when treated at 4°C for 2 days and 30°C for 2 and 5 days. Microspore-derived embryos (MDEs) were only obtained in the double-layer B5 medium supplemented with 2% sucrose which exposed to 4°C for 2 days and then 30°C for 2 and 5 days.  Microspore embryogenesis in tomato could be efficiently induced when appropriate duration of cold treatment, heat shock, and induction medium were selected.