Abstract: The ovules of Castanea mollissima Bl.were used as explants in this experiment to test the main active factors when cultured in vitro.These factors included hormone combinations,the collecting date to get ovules as well as the types and concentrations of carbohydrate source in the basic medium.The rush techniques used to overcome the difficulties existing in ovule culture in vitro of C.mollissima were also discussed in this paper.Results of the experiment indicated that:1) The optimal period to collect the bars for getting fitting ovules was about 30 to 44 days after the first full-blown florescence of C.mollissima in Huairou Zone of Beijing.2) When maintained C.mollissima's ovules in vitro,adding 2,4-D,6-BA and TDZ individually at the concentration level of 0.5 mg/L or 1.0 mg/L to WPM medium can not induce embryogenesis.3) While using cytokinins together with 2,4-D to basic medium,the variety and concentration of cytokinin in the medium affected embryogensis frequency greatly.The effects of adding 6-BA and 2,4-D simultaneously to the medium were pretty well than adding any one of KT,TDZ or ZT together with 2,4-D to the medium.And the analytic result also showed that adding 6.0 mg/L 2,4-D accompany with 0.5 mg/L 6-BA to the medium was effective to induce somatic embryos of C.mollissima.4) The concentration of 2,4-D contained in the medium,the sort and the concentration of cytokinins contained in the medium were all significant correlated with the frequency of embryonic callus induction.Adding 4.0 mg/L 2,4-D and 1.0 mg/L TDZ to the medium simultaneously was efficiently to induce embryonic callus in ovule culture in vitro of C.mollissima.5) White granulated sugar bought from food store was the best ingredient acting as the carbohydrate source when culturing ovules of C.mollissima in vitro and it was better than sucrose,glucose or maltose.6) 10-40 g/L of white granulated sugar contained in the medium all can induce embryogenesis of C.mollissima,but the death rate of the explants was rising with increasing the concentration of sugar.