The aim of the study was to assess the safety of methionine sulfoxide reductase B2(CaMsrB2) protein as toxicity, allergenecity and identity of inserted gene product that transformed rice. Through bioinfomatical research of CaMsrB2, amino acid sequence of CaMsrB2 did not share overall homology with any known or suspected to be allergen or toxin protein. For the biochemical research, CaMsrB2 protein was expressed and purified. Using purified protein, we made a specific antibody. Purified protein was sequenced by Edman degradation methods and confirmed sequence identify.. The amino acid sequences of purified protein were the same as deduced amino acid sequences exclude N-terminal Histidine. And for the internal sequences of CaMsrB2, we performed MALDI-TOF Mass. The results of MALDI-TOF MS was compared Mascot Database and confirmed the sequence coverage was 56%. These results mean bacterially produced CaMsrB2 was the same with inserted gene product. With these purified and identified CaMsrB2 protein, we performed acute toxicity test. Following the OECD guideline 423, 2,000mg/Kg body weight protein were injected as oral administration. After 2 weeks, there did not shown any death and special symptoms.