Random amplified polymorphic DNA(RAPD) was used in analyzing the polymorphisms of Thiobacillus ferrooxidans from seven different places. Of the 20 primers, four could generate reproducible RAPD profiles, and each one produced 1 approximately 9 bands. The similarity coefficients obtained from profiles generated by four primers among Thiobacillus Ferrooxidans were about 44% approximately 83%.