This study was conducted to investigate optimal conditions for formation of synnemata from Beauveria bassiana. The strain of B. bassiana was isolated from a host of Oncotympana fuscata in Halla mountain of Jeju island. The yield of synnemata was the highest at application of brown rice (90%) and silkworm pupae (10%) media. On the other hand, the other media did not result in formation of synnemata. The highest formation of synnemata was achieved at conditions of moderate air inflow and 20℃. The optimal moisture and light intensity for formation of synnemata were 60% and 300 lux, respectively. In addition, inoculation of the liquid spawn resulted in higher yield than that of asexual spore.