Abstract: Random amplified polymorphic DNA (RAPD) technique was employed in analyzing the specific genetic markers of seven pearl oysters including Pinctada maxima, P.margaritifera, P.nigra, P.albina, P.fucata, P.chemnitzi in the genus Pinctada and Pteria penguin in the genus Pteria. Twenty one primers of S series and OPM series were screened. Four primers produce 57 loci. The average number of loci amplified by each primer is 14.3. The mean number of fingerprints per species amplified by each primer is 4.9 with length varying from 250 to 2 000 bp. Primer S10 generate diagnostic markers for each species and can distinguish the seven species studied simultaneously. The other primers screened in this study can discriminate two or more species from the others.