The number of pest detection in wooden pellets has increased since wooden pellets as biomass-solid refuse fuel (Bio-SRF) was allowed an import in Korea. In this study, we analyzed an insecticidal effect on pupal and adult stages of red flour beetle (Tribolium castaneum) and maize weevil (Sitophilus zeamais) in wooden pellets using two fumigants, methyl bromide (MB) and phosphine (PH3), for establishing a guideline on fumigation. MB and PH3 both showed a dose-dependent manner in insect mortality after fumigation under 60% filing rate (FR) of wooded pellets in desiccator. In MB fumigation to T. castaneum, adults and pupae showed 100% mortality at 128 mg/L and 161 mg/L in 10°C at 24 h post treatment and pupae showed 100, 74, and 8% mortality against 99 mg/L of MB in 20, 40, and 40% FR, respectively. In PH3 fumigation, S. zeamais adults showed 92% mortality to 4 mg/L, meanwhile T. castaneum adults showed 100% mortality at 120 h post treatment.