A total of 248 arbitrary 10-mer oligonucleotide primers were screened using RAPD (random amplified polymorphic DNA) techniques with the genome DNA of three groups of three-line hybrid rice and their parents. Thirteen primers produced 43 polymorphism fragments. Six primers of them produced 20 obviously repeatable polymorphic markers among rice lines tested. Using this RAPD markers,the hybrid rice combinations (sterile-line, maintainer-line, restorer-line and F1) can be effectively identified, and the genetic relationship among them can be shown.