Purpose:To probe the variation of p53 mRNA transcriptions in of colorectal neoplasia.Methods:Tumor tissues, transitonal tissues and normal tissues of 9 cases of colorectal carcinomas and 3 case benign neoplasia were comparatively studied by reverse transcriptional polymerase chain reaction in stiu (RT PCRIS). Results:In 3 benign cases, only 1 positive was found in the tumor. In 9 malignant cases,the positives cases were: 7 in neoplastic tissues; 4 in transitional tissues; 1 in normal tissue.Conclusions:The results show that the variation of P53 mRNA transcription may occur in the early phase of colorectal neoplasia development, and that the positive rate of P53 mRNA by RT PCRIS is higher than the conventional immunohistochemistry (IHC). RT PCRIS analysis combined with organ conformation has very high accuracy and specificity