Many entomopathogenic fungal isolates received interests for controlling insect pests. But very few numbers of isolatesreached agricultural fields as commercial products. In this study, we investigated the feasibility of grain substrates forconidial production, focusing on conidial productivity and thermotolerance. Next to efficiently use the produced conidiafor spray application, conidia need to be separated from the grain substrates. Isaria javanica and I. fumosorosea conidiawere solid-cultured on ten kinds of cereal grains. Solid-cultured grains were packed in a screen bag and immersed inwater with a variety of surfactants at 100 ppm, such as Silwet, CO-2.5, CO-12, LE-7, PE-61, TDE-3, Tween 20 or Tween80. High levels of conidial release were observed on LE-7, TDE-3 and Tween80 treatments. This work suggests thatthe screen bag can be used to separated conidia from the cultured grains with the help of surfactants.