Abstract:Four kinds of processed rice products were extracted of genomic DNA by the following three methods: classic phenol/chloroform extraction method, CTAB precipitation extraction method and guanidine hydrochloride extraction method. The total DNA quantity can be extracted from different quantity of each processed rice product and the starting material (g) was 120 mg, 800 g and 2000 mg. The quality and quantity of extracted DNA were assayed by PCR with the primer pair SPS-F/SPS-R. Results indicated that all of extracted genomic DNA by the CTAB precipitation extraction method can be amplified by PCR with exception of 0.12 g starting material. So we concluded that the CTAB precipitation extraction method has the highest efficiency of extracting genomic DNA and has least inhibiting information on PCR.