Due to the high toxicity of aflatoxins and its effects on public health and animal wealth, food and feed. The determination of mycotoxins in commodities is the only way of control. The identification of aflatoxigenic Aspergillus isolates through detection of nor-1 gene was tried. Ochratoxin has been widely detected in cereal-derived products. Its production by A. ochraceous and its biosynthetic gene ocrA was evaluated. For this purpose, 500 different cereal samples were collected from different markets in Sharkia Province. Five strains of Aspergillus spp. have been screened for their ability to produce aflatoxins after cultivation in Czapek,s Dox media. Aflatoxin B1was detected in average amount 4.9- 200 ng/μl through using HPLC technique. A Real time PCR (RT-PCR) technique was applied to determine the gene expression of structural nor-1, which catalyzed the first step in aflatoxins biosynthetic pathway.