Abstract: In order to get the best reaction system and suitable primerof Perca fluviatilis, using Perca fluviatilis genomic DNA as templates，by L17（5^{4）orthogonal experiment table, four major factors（Taq enzyme, Mg2+, dNTP and primer）that greatly affected the results of RAPD were chosen and design to seek optimal reaction condition.For a 25 μL reaction system contain, the optimal compositions included 30 ng DNA template 1.5 μL, 10 μmol/L primer0.7 μL, 10×buffer2.5 μL, 5 μmol/L dNTPs 0.4 μL, 5U Taq polymerase 0.2 μL, 2.5 mmol/L MgCl2 3.0 μL；useing the optimal system, 10 random primers were selected from 50 primers, and determine the optimal annealing temperature.Key words: Perca fluviatilis RAPD-PCR Condition optimization Suitable primers Annealing temperature}