Worldwide, increasing numbers insecticide resistant insect is one of the main problem in agriculture not only in the field but also in the storage. The rusty grain beetle, Cryptolestes ferrugineus is one of the cosmopolitan insect that infests a wide range of stored cereals and related commodities. Until quite recently, phosphine (PH3) has been effective in controlling this species in worldwide including Korea. However, strongly resistant populations of RGB have been detected in Australia that could threaten market access of infested commodities. Resistant populations detected in Australia showed extremely high levels of resistance to phosphine, up to 1300 folds higher than that of susceptible strain. So here we tried to identify their phosphine resistance mechanism based on transcriptome analysis using RNaseq in adult stage. Over 10Gb were sequenced in each strains and some of specific P450 were over expressed in resistance strain.