Some indexes of food safety of transgenic papaya with the replicase gene of papaya ringspot virus（PRSV） were evaluated in this thesis.By means of biological informatics,the analysis between the sequence transformed to papaya and the allergen sequences from GenBank,EMBL databases,PIR databases,etc. indicated there were not continuously eight same amino acids compared to the eight classes of allergens，including peanut,soybean,nut,milk,egg,fish,shellfish and wheat.It could be inferred that the rep sequence transformed to papaya did not contain the known allergens. The fulllength rep gene of papaya ringspot virus was cloned into expression vector pET-28b(+) and the specific expression product was purified by Ni-NTA resin. Some protein were attempted to be renatured.Through imitated gastric juice and intestinal juice experiment, it had been further proved the protein product of Rep gene could be degraded in human beings’ digestive system,it was unlikely to cause to the human body to be allergic. From the transgenic and no-transgenic papaya,an endogenous poisonous substance called benzyl isothiocyanate（BITC）was respectively extracted by liquid phase extraction,concentrated and sent to China National Analytical Center,Guangzhou. The results of gas chromatography and biological statistical analysis showed that there was no distinct difference in transgenic and no-transgenic papaya.