In order to improve technical proceduce of embryogenic callus formation used for citrus breeding program, a study on the impact of culture condition to the culture and maintain of embryogenic callus has been implemented. The result showed that callus cultured on MT medium supplemented with 50 g/l sucrose, 2 mg/l BAP, 0.5 g/l malt extract for Valencia orange and 1 mg/l BAP, 0,5 g/l malt extract for Sanh mandarin were considered to be most favourable and the transfer callus from solid medium to liquid medium or to bioreactor system gave positive effect on embryogenesis callus in term of its formation and multiplication ratio.