Phosphine is a common pesticide used to control grain pests in Rice Processing Complex(RPC). However, increasing use of aluminum phosphide caused the occurrence of phosphine resistance pests. In this study, phosphine resistance pests collected at RPC in 2023 was investigated with FAO No. 16 test, Dihydrolipomaide dehydrogenase(DLD) test and amino acid mutation analysis to identify the occurrence of phosphine resistance in Korea. Tested pests were collected in the 7 province 35 region. As a result of the FAO test of 21 regions, all sample were phosphine sensitives. In DLD test and amino acid analysis, 7 region samples were weak resistances. It is required to inspect the RPC and other grain storage continuously to inhibit the widespread of resistant pest.